Research & Scholarship

Clinical Trials

We propose to combine lapatinib with RT alone in patients with locally advanced head and
neck cancer who cannot tolerate chemotherapy. The main objective of the study is to
determine the efficacy of combining concurrent radiation and lapatinib in terms of
time-to-progression (TTP) in this group of patients. In addition, we will determine the
2-year locoregional control rate (LRC), progression-free survival (PFS) and overall survival
(OS) in these patients. We will also evaluate the profile and frequency of late toxicity,
specifically mucosal and dermatologic toxicity, of the combination of lapatinib and RT in
patients with locally advanced head and neck squamous cell carcinoma (HNSCC).

Stanford is currently not accepting patients for this trial.For more information, please contact Brian Khong, (650) 725 - 4777.

Abstract

Assessment of patients with sinonasal malignancy is challenging due to the low disease incidence and diverse histopathology. The current literature is composed mainly of retrospective studies with heterogeneous cohorts, and the rarity of cases limits our understanding of disease characteristics and treatment outcomes. We describe the development of a prospective, multi-institutional registry that utilizes cloud-based computing to evaluate treatment outcomes in patients with sinonasal cancer.A web-based, secure database was built to prospectively capture longitudinal outcomes and quality-of-life (QoL) data in patients diagnosed with sinonasal malignancy. Demographics, tumor staging, and treatment outcomes data are being collected. The Sinonasal Outcome Test-22 and University of Washington Quality of Life Questionnaire are administered at presentation and at recurring intervals. To date, seven institutions are participating nationally.This prospective, multi-institutional registry will provide novel oncological and QoL outcomes on patients with sinonasal malignancy to inform management decisions and disease prognostication. The application of cloud-based computing facilitates secure multi-institutional collaboration and may serve as a model for future registry development for the study of rare diseases in otolaryngology.2C. Laryngoscope, 2016.

Abstract

Ameloblastoma is a rare odontogenic neoplasm of the mandible and maxilla, with multiple histologic variants, and high recurrence rates if improperly treated. The current mainstay of treatment is wide local excision with appropriate margins and immediate reconstruction. Here we review the ameloblastoma literature, using the available evidence to highlight the change in management over the past several decades. In addition, we explore the recent molecular characterization of these tumors which may point towards new potential avenues of personalized treatment.

Abstract

The risk of intracranial dural arteriovenous fistula is linked to its pattern of venous drainage (Borden type), in particular the presence of cortical venous drainage. The purpose of this study was to assetss the accuracy of 3D pseudocontinuous arterial spin-labeling (ASL) MRI for noninvasive delineation of venous drainage.This retrospective study included 34 patients with a dural arteriovenous fistula who had undergone both digital subtraction angiography (DSA) and 3D pseudocontinuous ASL MRI. Two neuroradiologists blinded to the DSA results independently assessed ASL images for the presence of cortical vein hyperintensity (cortical venous drainage) and the distribution of venous hyperintensity (Borden type). DSA was used as the reference standard. The sensitivity and specificity of 3D pseudocontinuous ASL MRI for the detection of cortical venous drainage were determined. Intermodality and interobserver agreement for Borden type was determined by use of the weighted kappa statistic.Three-dimensional pseudocontinuous ASL MRI had high sensitivity (91%) and specificity (96%) for the detection of cortical venous drainage. Borden type was correctly identified with very good intermodality (weighted κ = 0.82) and interobserver (weighted κ = 0.85) agreement in 88% of patients.Three-dimensional pseudocontinuous ASL MRI is highly accurate for the detection of cortical venous drainage and determination of Borden type. With this technique, high-risk fistulas requiring treatment can be reliably differentiated from low-risk lesions. Although it cannot replace DSA, incorporating 3D pseudocontinuous ASL into an MRI protocol for assessment of dural arteriovenous fistula can facilitate treatment planning.

Abstract

A neuroradiologist's activity includes many tasks beyond interpreting relative value unit-generating imaging studies. Our aim was to test a simple method to record and quantify the non-relative value unit-generating clinical activity represented by consults and clinical conferences, including tumor boards.Four full-time neuroradiologists, working an average of 50% clinical and 50% academic activity, systematically recorded all the non-relative value unit-generating consults and conferences in which they were involved during 3 months by using a simple, Web-based, computer-based application accessible from smartphones, tablets, or computers. The number and type of imaging studies they interpreted during the same period and the associated relative value units were extracted from our billing system.During 3 months, the 4 neuroradiologists working an average of 50% clinical activity interpreted 4241 relative value unit-generating imaging studies, representing 8152 work relative value units. During the same period, they recorded 792 non-relative value unit-generating study reviews as part of consults and conferences (not including reading room consults), representing 19% of the interpreted relative value unit-generating imaging studies.We propose a simple Web-based smartphone app to record and quantify non-relative value unit-generating activities including consults, clinical conferences, and tumor boards. The quantification of non-relative value unit-generating activities is paramount in this time of a paradigm shift from volume to value. It also represents an important tool for determining staffing levels, which cannot be performed on the basis of relative value unit only, considering the importance of time spent by radiologists on non-relative value unit-generating activities. It may also influence payment models from medical centers to radiology departments or practices.

Abstract

Patients with tumors adjacent to the optic nerves and chiasm are frequently not candidates for single-fraction stereotactic radiosurgery (SRS) due to concern for radiation-induced optic neuropathy. However, these patients have been successfully treated with hypofractionated SRS over 2-5 days, though dose constraints have not yet been well defined. We reviewed the literature on optic tolerance to radiation and constructed a dose-response model for visual pathway tolerance to SRS delivered in 1-5 fractions. We analyzed optic nerve and chiasm dose-volume histogram (DVH) data from perioptic tumors, defined as those within 3mm of the optic nerves or chiasm, treated with SRS from 2000-2013 at our institution. Tumors with subsequent local progression were excluded from the primary analysis of vision outcome. A total of 262 evaluable cases (26 with malignant and 236 with benign tumors) with visual field and clinical outcomes were analyzed. Median patient follow-up was 37 months (range: 2-142 months). The median number of fractions was 3 (1 fraction n = 47, 2 fraction n = 28, 3 fraction n = 111, 4 fraction n = 10, and 5 fraction n = 66); doses were converted to 3-fraction equivalent doses with the linear quadratic model using α/β = 2Gy prior to modeling. Optic structure dose parameters analyzed included Dmin, Dmedian, Dmean, Dmax, V30Gy, V25Gy, V20Gy, V15Gy, V10Gy, V5Gy, D50%, D10%, D5%, D1%, D1cc, D0.50cc, D0.25cc, D0.20cc, D0.10cc, D0.05cc, D0.03cc. From the plan DVHs, a maximum-likelihood parameter fitting of the probit dose-response model was performed using DVH Evaluator software. The 68% CIs, corresponding to one standard deviation, were calculated using the profile likelihood method. Of the 262 analyzed, 2 (0.8%) patients experienced common terminology criteria for adverse events grade 4 vision loss in one eye, defined as vision of 20/200 or worse in the affected eye. One of these patients had received 2 previous courses of radiotherapy to the optic structures. Both cases were meningiomas treated with 25Gy in 5 fractions, with a 3-fraction equivalent optic nerve Dmax of 19.2 and 22.2Gy. Fitting these data to a probit dose-response model enabled risk estimates to be made for these previously unvalidated optic pathway constraints: the Dmax limits of 12Gy in 1 fraction from QUANTEC, 19.5Gy in 3 fractions from Timmerman 2008, and 25Gy in 5 fractions from AAPM Task Group 101 all had less than 1% risk. In 262 patients with perioptic tumors treated with SRS, we found a risk of optic complications of less than 1%. These data support previously unvalidated estimates as safe guidelines, which may in fact underestimate the tolerance of the optic structures, particularly in patients without prior radiation. Further investigation would refine the estimated normal tissue complication probability for SRS near the optic apparatus.

Abstract

Metronidazole is a nitroimidazole antimicrobial drug prescribed to treat infections caused by anaerobic bacteria and protozoa. Uncommonly, it causes central nervous system (CNS) toxicity manifesting as metronidazole-induced encephalopathy (MIE).Case report.A 65-year-old woman with hepatitis B cirrhosis (Child-Pugh class C, MELD 21) developed progressive encephalopathy to GCS 4 during a 3-week course of metronidazole for cholecystitis. Initial MRI was consistent with CNS metronidazole toxicity, with symmetrical T2 hyperintensity and generally restricted diffusion in bilateral dentate nuclei, corpus callosum, midbrain, superior cerebellar peduncles, internal capsules, and cerebral white matter. Laboratory values did not demonstrate significant electrolyte shifts, and continuous EEG was without seizure. High-dose thiamine was empirically administered. Lumbar puncture was not performed due to coagulopathy and thrombocytopenia. Despite discontinuation of metronidazole and keeping ammonia levels near normal, the patient did not improve. MRI was repeated 1 week after discontinuation of metronidazole. Although there was decreased DWI hyperintensity in the dentate nuclei, diffuse T2 hyperintensity persisted and even progressed in the brainstem, basal ganglia, and subcortical white matter. Petechial hemorrhages developed in bilateral corticospinal tracts and subcortical white matter. T1 hypointensity appeared in the corpus callosum. She was transitioned to comfort measures only and died 12 days later.MIE is an uncommon adverse effect of treatment with metronidazole that characteristically affects the dentate nuclei but may also involve the brainstem, corpus callosum, subcortical white matter, and basal ganglia. While the clinical symptoms and neuroimaging changes are usually reversible, persistent encephalopathy with poor outcome may occur.

Abstract

To develop a qualitative brain magnetic resonance imaging (MRI) scoring system for comatose cardiac arrest patients that can be used in clinical practice.Consecutive comatose postcardiac arrest patients were prospectively enrolled. Routine MR brain sequences were scored by two independent blinded experts. Predefined brain regions were qualitatively scored on the fluid-attenuated inversion recovery (FLAIR) and diffusion-weighted imaging (DWI) sequences according to the severity of the abnormality on a scale from 0 to 4. The mean score of the raters was used. Poor outcome was defined as death or vegetative state at 6 months.Sixty-eight patients with 88 brain MRI scans were included. Median time from the arrest to the initial MRI was 77 hours (IQR 58-144 hours). At 100% specificity, the "cortex score" performed best in predicting unfavorable outcome with a sensitivity of 55%-60% (95% CI 41-74) depending on time window selection. When comparing the "cortex score" with historically used predictors for poor outcome, MRI improved the sensitivity for poor outcome over conventional predictors by 27% at 100% specificity.A qualitative MRI scoring system helps assess hypoxic-ischemic brain injury severity following cardiac arrest and may provide useful prognostic information in comatose cardiac arrest patients.

Abstract

The development of new imaging techniques coupled with new treatment algorithms has created new possibilities in treating temporal bone diseases. This article provides an overview of recent imaging innovations that can be applied to temporal bone diseases. Topics covered include the role of magnetic resonance (MR) diffusion-weighted imaging in cholesteatomas and skull base epidermoids, whole-body molecular imaging in paragangliomas of the jugular foramen, and MR arterial spin labeling perfusion for dural arteriovenous fistulas and arteriovenous malformations.

Abstract

To investigate the frequency and characteristics of developmental venous anomaly (DVA)-associated perfusion abnormalities on arterial spin labeling (ASL) and bolus perfusion-weighted imaging (PWI) and discuss their potential causes.We reviewed brain MR reports to identify all DVAs reported on studies performed between 2009 and 2012. DVA location and findings on PWI and/or ASL imaging were assessed by visual inspection. Sizes of DVAs were categorized as small (<15 mm), medium (15-25 mm), and large (>25 mm). For ASL, signal in the DVA, surrounding parenchyma, or associated draining vein was recorded. For PWI, changes on hemodynamic maps (cerebral blood volume [CBV], cerebral blood flow [CBF], mean transit time [MTT], and normalized time-to-peak of the residue function [Tmax]) were evaluated. Coexisting vascular malformations in association with DVAs were also identified.Six hundred and fifty-two DVAs were identified in 632 subjects. Of these, 121 underwent both perfusion modalities, 15 only PWI, and 127 only ASL. ASL abnormalities were seen in 21/248 (8%), including signal in a draining vein (2/21, 10%), in the DVA (11/21, 52%), and in the parenchyma (8/21, 38%). On PWI, the majority of DVAs demonstrated abnormalities (108/136, 79%), typically increased CBF, CBV, MTT, and Tmax. There was no association between DVA size and presence of ASL signal (P = .836). Borderline statistical significance was found between DVA size and presence of PWI abnormality (P = .046). No relationship was found between the presence of a coexisting vascular malformation and presence of ASL (P = .468) or PWI abnormality (P = .745).Perfusion changes with DVAs are common on PWI but uncommon on ASL. PWI findings are expected based on the anatomy and physiology of DVAs and are accentuated by gradient echo acquisition. DVAs with intrinsic ASL signal or signal in draining veins may be associated with arteriovenous shunting (transitional lesions).

Abstract

Dural arteriovenous fistulae (DAVF) are cerebrovascular lesions with pathologic shunting into the venous system from arterial feeders. Digital subtraction angiography (DSA) has long been considered the gold standard for diagnosis, but advances in noninvasive imaging techniques now play a role in the diagnosis of these complex lesions. Herein, we describe the case of a patient with right-side pulsatile tinnitus and DAVF diagnosed using computed tomography angiography, magnetic resonance with arterial spin labeling, and DSA. Implications for imaging analysis of DAVFs and further research are discussed.

Abstract

Imaging of the skull base presents many challenges due to its anatomical complexity, numerous normal variants and lack of familiarity to many radiologists. As the skull base is a region which is not amenable to physical examination and as lesions of the skull base are generally difficult to biopsy and even more difficult to operate on, the radiologist plays a major role in directing patient management via accurate image interpretation. Knowledge of the skull base should not be limited to neuroradiologists and head and neck radiologists, however, as the central skull base is routinely included in the field of view when imaging the brain, cervical spine, or head and neck with computed tomography or magnetic resonance imaging, and hence, its nuances should be familiar to general radiologists as well. We herein review the imaging findings of a subcategory of lesions of the central skull base, the 'do not touch' lesions.

Abstract

Parallel imaging facilitates the acquisition of echo-planar images with a reduced TE, enabling the incorporation of an additional image at a later TE. Here we investigated the use of a parallel imaging-enhanced dual-echo EPI sequence to improve lesion conspicuity in diffusion-weighted imaging.Parallel imaging-enhanced dual-echo DWI data were acquired in 50 consecutive patients suspected of stroke at 1.5T. The dual-echo acquisition included 2 EPI for 1 diffusion-preparation period (echo 1 [TE = 48 ms] and echo 2 [TE = 105 ms]). Three neuroradiologists independently reviewed the 2 echoes by using the routine DWI of our institution as a reference. Images were graded on lesion conspicuity, diagnostic confidence, and image quality. The apparent diffusion coefficient map from echo 1 was used to validate the presence of acute infarction. Relaxivity maps calculated from the 2 echoes were evaluated for potential complementary information.Echo 1 and 2 DWIs were rated as better than the reference DWI. While echo 1 had better image quality overall, echo 2 was unanimously favored over both echo 1 and the reference DWI for its high sensitivity in detecting acute infarcts.Parallel imaging-enhanced dual-echo diffusion-weighted EPI is a useful method for evaluating lesions with reduced diffusivity. The long TE of echo 2 produced DWIs that exhibited superior lesion conspicuity compared with images acquired at a shorter TE. Echo 1 provided higher SNR ADC maps for specificity to acute infarction. The relaxivity maps may serve to complement information regarding blood products and mineralization.

Abstract

The objectives of this study were to acquire ultra-high resolution images of the brain using balanced steady-state free precession (bSSFP) at 7.0 T and to identify the potential utility of this sequence.Eight volunteers participated in this study after providing informed consent. Each volunteer was scanned with 8 phase cycles of bSSFP at 0.4-mm isotropic resolution using 0.5 number of excitations and 2-dimensional parallel acceleration of 1.75 × 1.75. Each phase cycle required 5 minutes of scanning, with pauses between the phase cycles allowing short periods of rest. The individual phase cycles were aligned and then averaged. The same volunteers underwent scanning using 3-dimensional (3D) multiecho gradient recalled echo at 0.8-mm isotropic resolution, 3D Cube T2 at 0.7-mm isotropic resolution, and thin-section coronal oblique T2-weighted fast spin echo at 0.22 × 0.22 × 2.0-mm resolution for comparison. Two neuroradiologists assessed image quality and potential research and clinical utility.The volunteers generally tolerated the scan sessions well, and composite high-resolution bSSFP images were produced for each volunteer. Rater analysis demonstrated that bSSFP had a superior 3D visualization of the microarchitecture of the hippocampus, very good contrast to delineate the borders of the subthalamic nucleus, and relatively good B1 homogeneity throughout. In addition to an excellent visualization of the cerebellum, subtle details of the brain and skull base anatomy were also easier to identify on the bSSFP images, including the line of Gennari, membrane of Liliequist, and cranial nerves. Balanced steady-state free precession had a strong iron contrast similar to or better than the comparison sequences. However, cortical gray-white contrast was significantly better with Cube T2 and T2-weighted fast spin echo.Balanced steady-state free precession can facilitate ultrahigh-resolution imaging of the brain. Although total imaging times are long, the individually short phase cycles can be acquired separately, improving examination tolerability. These images may be beneficial for studies of the hippocampus, iron-containing structures such as the subthalamic nucleus and line of Gennari, and the basal cisterns and their contents.

Abstract

A 39-year-old woman presented with a right-hemispheric stroke 1 year after she had suffered a left-hemispheric stroke. Her diagnostic workup was notable for bilateral occlusions of the internal carotid arteries at their origins and a positive lupus anticoagulant antibody test. There was no evidence of carotid dissection or another identifiable cause for her carotid occlusions. These findings suggest that the antiphospholipid antibody syndrome may be implicated in the pathological changes that resulted in occlusions of the extracranial internal carotid arteries. Young stroke patients who present with unexplained internal carotid artery occlusions may benefit from testing for the presence of antiphospholipid antibodies.

Abstract

Evaluation of neurodegenerative disease progression may be assisted by quantification of the volume of structures in the human brain using magnetic resonance imaging (MRI). Automated segmentation software has improved the feasibility of this approach, but often the reliability of measurements is uncertain. We have established a unique dataset to assess the repeatability of brain segmentation and analysis methods. We acquired 120 T1-weighted volumes from 3 subjects (40 volumes/subject) in 20 sessions spanning 31 days, using the protocol recommended by the Alzheimer's Disease Neuroimaging Initiative (ADNI). Each subject was scanned twice within each session, with repositioning between the two scans, allowing determination of test-retest reliability both within a single session (intra-session) and from day to day (inter-session). To demonstrate the application of the dataset, all 3D volumes were processed using FreeSurfer v5.1. The coefficient of variation of volumetric measurements was between 1.6% (caudate) and 6.1% (thalamus). Inter-session variability exceeded intra-session variability for lateral ventricle volume (P<0.0001), indicating that ventricle volume in the subjects varied between days.

Abstract

The purpose of this study was to define the incidence, imaging characteristics, natural history, and prognostic implication of corticospinal tract Wallerian degeneration (CST-WD) in spontaneous intracerebral hemorrhage (ICH) using serial MR imaging.Consecutive ICH patients with supratentorial ICH prospectively underwent serial MRIs at 2, 7, 14, and 21 days. MRIs were analyzed by independent raters for the presence and topographical distribution of CST-WD on diffusion-weighted imaging (DWI). Baseline demographics, hematoma characteristics, ICH score, and admission National Institute of Health Stroke Score (NIHSS) were systematically recorded. Functional outcome at 3 months was assessed by the modified Rankin Scale (mRS) and the motor-NIHSS. Twenty-seven patients underwent 93 MRIs; 88 of these were serially obtained in the first month. In 13 patients (48%), all with deep ICH, CST-WD changes were observed after a median of 7 days (interquartile range, 7 to 8) as reduced diffusion on DWI and progressed rostrocaudally along the CST. CST-WD changes evolved into T2-hyperintense areas after a median of 11 days (interquartile range, 6 to 14) and became atrophic on MRIs obtained after 3 months. In univariate analyses, the presence of CST-WD was associated with poor functional outcome (ie, mRS 4 to 6; P=0.046) and worse motor-NIHSS (5 versus 1, P=0.001) at 3 months.Wallerian degeneration along the CST is common in spontaneous supratentorial ICH, particularly in deep ICH. It can be detected 1 week after ICH on DWI and progresses rostrocaudally along the CST over time. The presence of CST-WD is associated with poor motor and functional recovery after ICH.

Abstract

Spontaneous intracerebral hemorrhage (ICH) is associated with blood-brain barrier (BBB) injury, which is a poorly understood factor in ICH pathogenesis, potentially contributing to edema formation and perihematomal tissue injury. We aimed to assess and quantify BBB permeability following human spontaneous ICH using dynamic contrast-enhanced magnetic resonance imaging (DCE MRI). We also investigated whether hematoma size or location affected the amount of BBB leakage.Twenty-five prospectively enrolled patients from the Diagnostic Accuracy of MRI in Spontaneous intracerebral Hemorrhage (DASH) study were examined using DCE MRI at 1 week after symptom onset. Contrast agent dynamics in the brain tissue and general tracer kinetic modeling were used to estimate the forward leakage rate (K(trans)) in regions of interest (ROI) in and surrounding the hematoma and in contralateral mirror-image locations (control ROI). In all patients BBB permeability was significantly increased in the brain tissue immediately adjacent to the hematoma, that is, the hematoma rim, compared to the contralateral mirror ROI (P<0.0001). Large hematomas (>30 mL) had higher K(trans) values than small hematomas (P<0.005). K(trans) values of lobar hemorrhages were significantly higher than the K(trans) values of deep hemorrhages (P<0.005), independent of hematoma volume. Higher K(trans) values were associated with larger edema volumes.BBB leakage in the brain tissue immediately bordering the hematoma can be measured and quantified by DCE MRI in human ICH. BBB leakage at 1 week is greater in larger hematomas as well as in hematomas in lobar locations and is associated with larger edema volumes.

Abstract

: To report outcomes, failure patterns, and toxicity after stereotactic radiosurgery (SRS) for recurrent head and neck cutaneous squamous cell carcinoma with gross perineural invasion (GPNI).: Ten patients who received SRS as part of retreatment for recurrent head and neck cutaneous squamous cell carcinoma with GPNI were included. All patients exhibited clinical and radiologic evidence of GPNI before SRS. Previous treatments included surgery alone in 3 patients and surgery with adjuvant external beam radiotherapy (EBRT) in 7 patients. Retreatment included SRS alone in 2 and EBRT boosted with SRS in 8 patients. Magnetic resonance images were obtained every 3 to 6 months after SRS to track failure patterns.: At a median 22-month follow-up, the 2-year progression-free and overall survival rates were 20% and 50%, respectively. Seven patients exhibited local failures, all of which occurred outside both SRS and EBRT fields. Five local failures occurred in previously clinically uninvolved cranial nerves (CNs). CN disease spreads through 3 distinct patterns: among different branches of CN V; between CNs V and VII; and between V1 and CNs III, IV, and/or VI. Five patients experienced side effects potentially attributable to radiation.: Although there is excellent in-field control with this approach, the rate of out-of-field failures remains unacceptably high. We found that the majority of failures occurred in previously clinically uninvolved CNs often just outside treatment fields. Novel treatment strategies targeting this mode of perineural spread are needed.

Abstract

Chordoma and chondrosarcoma of the skull base are rare tumors with overlapping presentations and anatomic imaging features but different prognoses. We hypothesized that these tumors might be distinguished by using diffusion-weighted MR imaging.We retrospectively reviewed 19 patients with pathologically confirmed chordoma or chondrosarcoma who underwent both conventional and diffusion-weighted MR imaging. Differences in distributions of ADC were assessed by the Kruskal-Wallis test. Associations between histopathologic diagnosis and conventional MR imaging features (T2 signal intensity, contrast enhancement, and tumor location) were assessed with the Fisher exact test.Chondrosarcoma was associated with the highest mean ADC value (2051 ± 261 × 10(-6) mm(2)/s) and was significantly different from classic chordoma (1474 ± 117 × 10(-6) mm(2)/s) and poorly differentiated chordoma (875 ± 100 × 10(-6) mm(2)/s) (P < .001). Poorly differentiated chordoma was characterized by low T2 signal intensity (P = .001), but other conventional MR imaging features of enhancement and/or lesion location did not reliably distinguish these tumor types.Diffusion-weighted MR imaging may be useful in assessing clival tumors, particularly in differentiating chordoma from chondrosarcoma. A prospective study of a larger cohort will be required to determine the value of ADC in predicting histopathologic diagnosis.

Abstract

To describe the accuracy of non-echo-planar diffusion-weighted magnetic resonance imaging (DW MRI) in identifying middle ear cholesteatoma.A meta-analysis of the published literature.A systematic review of the literature was performed to identify studies in which patients suspected of having middle ear cholesteatoma underwent DW MRI scans prior to surgery. A meta-analysis of the included studies was performed.Ten published articles (342 patients) met inclusion criteria. Cholesteatoma was confirmed in 234 patients, of which 204 were detected by DW MRI (true positives) and 30 were not (false negatives). One hundred eight patients did not have cholesteatoma on surgical examination, and of these 100 were correctly identified by MRI (true negatives) whereas eight were not (false positives). The overall sensitivity of DW MRI in detecting cholesteatoma was 0.94 (confidence interval, 0.80-0.98) and specificity 0.94 (confidence interval, 0.85-0.98). DW MRI sequences could not reliably detect cholesteatomas under 3 mm in size.Non-echo-planar DW MRI is highly sensitive and specific in identifying middle ear cholesteatoma. DW MRI may help to stratify patients into groups of who would benefit from early second-look surgery and those who could be closely observed.2a.

Abstract

DWI has the potential to improve the detection and evaluation of spine and spinal cord pathologies. This study assessed whether a recently described method (rFOV DWI) adds diagnostic value in clinical patients.Consecutive patients undergoing clinically indicated cervical and/or thoracic spine imaging received standard anatomic sequences supplemented with sagittal rFOV DWI by using a b-value of 500 s/mm(2). Two neuroradiologists blinded to clinical history evaluated the standard anatomic sequences only for pathology and provided their level of confidence in their diagnosis. These readers then rescored the examinations after reviewing the rFOV DWI study and indicated whether this sequence altered findings or confidence levels.Two hundred twenty-three patients were included in this study. One hundred eighty patient scans (80.7%) demonstrated at least 1 pathologic finding. Interobserver agreement for identifying pathology (? = 0.77) and in assessing the added value of the rFOV DWI sequence (? = 0.77) was high. In pathologic cases, the rFOV DWI sequence added clinical utility in 33% of cases (P < .00001, Fisher exact test). The rFOV DWI sequence was found to be helpful in the evaluation of acute infarction, demyelination, infection, neoplasm, and intradural and epidural collections (P < .001, ?(2) test) and provided a significant increase in clinical confidence in the evaluation of 11 of the 15 pathologic subtypes assessed (P < .05, 1-sided paired Wilcoxon test).rFOV diffusion-weighted imaging of the cervical and thoracic spine is feasible in a clinical population and increases clinical confidence in the diagnosis of numerous common spinal pathologies.

Abstract

Moyamoya disease (MM) is a rare disorder of the cerebral arterial circulation, whereas multiple sclerosis (MS) is a relatively common immune-mediated attack on central myelin. Despite the differences in pathogenesis, the 2 disorders share some clinical features which can lead to diagnostic confusion: both can affect young adults, cause intermittent neurological symptoms, and show multifocal abnormalities on brain imaging.To emphasize the need for early consideration of MM in the differential diagnosis of MS-spectrum disorders.Chart reviews and individual case analyses.We present detailed descriptions of 3 patients with MM, and summary data on 8 additional cases, in which there was diagnostic confusion with MS, with delays in treatment ranging from 2 months to 19 years (median=4 y).MM can be misdiagnosed as MS, leading to delay in correct treatment. We highlight the clinical and radiologic features which allow differentiation of these conditions early in the course, when treatment can have maximum benefit.

Abstract

CCSVI hypothesizes an association between impaired extracranial venous drainage and MS. Published sonographic criteria for CCSVI are controversial, and no MR imaging data exist to support the CCSVI hypothesis. Our purpose was to evaluate possible differences in the extracranial venous drainage of MS and healthy controls using both TOF and contrast-enhanced TRICKS MRV.Healthy subjects (n = 20) and patients with MS (n = 19) underwent axial 2D-TOF neck MRV (to assess flattening) and TRICKS MRV (to assess collaterals) at 3T. Two neuroradiologists blinded to cohort status scored IJV flattening and the severity of non-IJV collaterals by using a 4-point qualitative scale (normal = 0, mild = 1, moderate = 2, severe = 3). ? was used to assess reader agreement. Comparisons between groups were performed by using the Wilcoxon rank sum test. The Spearman rank correlation was used to assess the relationship between IJV flattening and collateral scores and, in patients with MS, EDSS scores.The 2 groups were matched for age and sex (MS, 45 ± 8 years, 79% female; healthy controls, 47 ± 10 years, 65% female). Reader agreement for IJV flattening and collateral severity was good (? = 0.74) and moderate (? = 0.58), respectively. While IJV flattening was seen in both patients with MS and healthy controls, scores for the patients with MS were significantly higher (P = .002). Despite a trend, there was no significant difference in collateral scores between groups (P = .063). There was a significant positive correlation between flattening and collateral scores (? = 0.32, P = .005) and EDSS and flattening scores (? = 0.45, P = .004) but not between EDSS and collateral scores (? = 0.01, P = .97).These results indicate that patients with MS have greater IJV flattening and a trend toward more non-IJV collaterals than healthy subjects. The role that this finding plays in the pathogenesis or progression of MS, if any, requires further study.

Abstract

To determine a radiographic association between superior semicircular canal dehiscence (SSCD) and tegmen dehiscence (TD).Retrospective case-control series.Tertiary referral center.Patients seen between 2003 and 2010 with radiographic SSCD were compared with cochlear implant recipient controls.The tegmen and superior semicircular canal were evaluated on computed tomographic temporal bone scans.If detected, the widest point of the SSCD was measured. The tegmen was graded on a 5-point scale. After analysis, a radiographic TD was defined as any single area of absent tegmen greater than 5 mm, multiple areas of absent tegmen, or evidence of meningocele. Age, sex, and body mass index were also noted.Thirty-eight patients with SSCD and 41 cochlear implant controls were identified. Seventy-six percent (29/38) of patients with unilateral or bilateral SSCD had a radiographic TD on at least 1 side compared with 22% (9/41) of the comparison group. Ninety-four percent (7/18) of patients with bilateral SSCD had a TD on at least 1 side. Patients with SSCD had a 10.2 times (p < 0.001) higher odds of having radiographic TD in either ear compared to the controls. Among patients with any SSCD, for every millimeter increase in the width of dehiscence, the relative risk for any TD increased more than 2-fold (odds ratio, 2.5; p = 0.019). Age, sex, and a body mass index greater than 30 did not confound the association between SSCD and TD.There is a strong radiologic association between SSCD and TD, suggesting a similar etiologic process. The tegmen should be carefully evaluated in patients with SSCD. We have also proposed a new system for radiographically grading the integrity of the tegmen.

Abstract

PI improves routine EPI-based DWI by enabling higher spatial resolution and reducing geometric distortion, though it remains unclear which of these is most important. We evaluated the relative contribution of these factors and assessed their ability to increase lesion conspicuity and diagnostic confidence by using a GRAPPA technique.Four separate DWI scans were obtained at 1.5T in 48 patients with independent variation of in-plane spatial resolution (1.88 mm(2) versus 1.25 mm(2)) and/or reduction factor (R = 1 versus R = 3). A neuroradiologist with access to clinical history and additional imaging sequences provided a reference standard diagnosis for each case. Three blinded neuroradiologists assessed scans for abnormalities and also evaluated multiple imaging-quality metrics by using a 5-point ordinal scale. Logistic regression was used to determine the impact of each factor on subjective image quality and confidence.Reference standard diagnoses in the patient cohort were acute ischemic stroke (n = 30), ischemic stroke with hemorrhagic conversion (n = 4), intraparenchymal hemorrhage (n = 9), or no acute lesion (n = 5). While readers preferred both a higher reduction factor and a higher spatial resolution, the largest effect was due to an increased reduction factor (odds ratio, 47 ± 16). Small lesions were more confidently discriminated from artifacts on R = 3 images. The diagnosis changed in 5 of 48 scans, always toward the reference standard reading and exclusively for posterior fossa lesions.PI improves DWI primarily by reducing geometric distortion rather than by increasing spatial resolution. This outcome leads to a more accurate and confident diagnosis of small lesions.

Abstract

The perfusion-weighted imaging (PWI)-diffusion-weighted imaging (DWI) mismatch paradigm is widely used in stroke imaging studies. Arterial spin labeling (ASL) is an alternative perfusion method that does not require contrast. This study compares the agreement of ASL-DWI and PWI-DWI mismatch classification in patients with stroke.This was a retrospective study drawn from all 1.5-T MRI studies performed in 2010 at a single institution. Inclusion criteria were: symptom onset<5 days, DWI lesion>10 mL, and acquisition of both PWI and ASL. DWI and PWI time to maximum>6 seconds lesion volumes were determined using automated software. Patients were classified into reperfused, matched, or mismatch groups. Two radiologists classified ASL-DWI qualitatively into the same categories blinded to DWI-PWI. Agreement between both individual readers and methods was assessed.Fifty-one studies met the inclusion criteria. Seven cases were excluded (1 due to PWI susceptibility artifact, 2 due to motion, and 4 due to severe ASL border zone sign), resulting in 44 studies for comparison. Interrater agreement for ASL-DWI mismatch status was high (?=0.92; 95% CI, 0.80-1.00). ASL-DWI and PWI-DWI mismatch categories agreed in 25 of 44 cases (57%). In the 16 of 19 discrepant cases (84%), ASL overestimated the PWI lesion size. In 34 of 44 cases (77%), they agreed regarding the presence of mismatch versus no mismatch.Mismatch classification based on ASL and PWI agrees frequently but not perfectly. ASL tends to overestimate the PWI time to maximum lesion volume. Improved ASL methodologies and/or higher field strength are necessary before ASL can be recommended for routine use in acute stroke.

Abstract

To report outcomes in patients treated with intensity-modulated radiotherapy (IMRT) for tumors of the paranasal sinuses and nasal cavity (PNS/NC).Between June 2000 and December 2009, 52 patients with tumors of the PNS/NC underwent postoperative or definitive radiation with IMRT. Twenty-eight (54%) patients had squamous cell carcinoma (SCC). Twenty-nine patients (56%) received chemotherapy. The median follow-up was 26.6 months (range, 2.9-118.4) for all patients and 30.9 months for living patients.Eighteen patients (35%) developed local-regional failure (LRF) at median time of 7.2 months. Thirteen local failures (25%) were observed, 12 in-field and 1 marginal. Six regional failures were observed, two in-field and four out-of-field. No patients treated with elective nodal radiation had nodal regional failure. Two-year local-regional control (LRC), in-field LRC, freedom from distant metastasis (FFDM), and overall survival (OS) were 64%, 74%, 71%, and 66% among all patients, respectively, and 43%, 61%, 61%, and 53% among patients with SCC, respectively. On multivariate analysis, SCC and >1 subsite involved had worse LRC (p = 0.0004 and p = 0.046, respectively) and OS (p = 0.003 and p = 0.046, respectively). Cribriform plate invasion (p = 0.005) and residual disease (p = 0.047) also had worse LRC. Acute toxicities included Grade ?3 mucositis in 19 patients (37%), and Grade 3 dermatitis in 8 patients (15%). Six patients had Grade ?3 late toxicity including one optic toxicity.IMRT for patients with PNS/NC tumors has good outcomes compared with historical series and is well tolerated. Patients with SCC have worse LRC and OS. LRF is the predominant pattern of failure.

Abstract

Papillary endothelial hyperplasia (PEH) is a rare form of exuberant reactive endothelial proliferation that can mimic neoplasm. We report the largest series of patients with histologically confirmed intracranial extravascular PEH developing in the field of previous treatment with stereotactic radiosurgery.We collected the clinical, radiological, surgical, and pathological findings from 4 patients in whom intracranial extravascular PEH developed after treatment with stereotactic radiosurgery. In all patients, the development of an enlarging hemorrhagic mass lesion at the site of previous radiotherapy on magnetic resonance imaging was radiographically suspicious for neoplasm and prompted biopsy or resection. All 4 patients elected to undergo biopsy or surgical resection. Histological examination of the biopsy and resection specimens in all patients demonstrated the classic features of PEH.The interval to the development of PEH ranged from 5 months to 6 years, 10 months. Clinical follow-up was available for 3 of the 4 patients. None of these 3 patients have demonstrated evidence of recurrence during a mean follow-up period of 22 months (range, 15-30 months). These patients share common radiological features, potentially allowing preoperative diagnosis and improved guidance of clinical management. These cases suggest a link between radiosurgery and the development of PEH. These findings also suggest that PEH should be considered in the differential diagnosis for patients treated with radiosurgery in whom a hemorrhagic mass lesion subsequently develops at or near the site of previous treatment. We think that complete surgical excision is the best treatment for intracranial PEH.

Abstract

DAVFs and small AVMs are difficult to detect on conventional MR imaging/MRA or CTA examinations and often require DSA for definitive diagnosis. The purpose of this study was to assess the value of venous signal intensity on ASL imaging for making this diagnosis.Two neuroradiologists and 1 neurologist reviewed MR imaging studies in 26 patients, 15 of whom had DSA-proved DAVFs or small (<2 cm) AVMs. Pseudocontinuous ASL was performed at 1.5T with background-suppressed 3D-FSE readout. Using a 5-point scale, these readers assessed the likelihood of positive findings on a DSA study before and after reviewing the ASL findings. Agreement on imaging findings, including venous ASL signal intensity, was performed by using ? statistics. Logistic regression and ROC analysis were performed to determine which imaging findings improved diagnosis.Venous ASL signal intensity was seen frequently in cases with positive findings on DSA. The sensitivity and specificity of venous ASL signal intensity for predicting positive findings on a DSA study were 78% and 85%, respectively. On ROC analysis, there was a significant increase in the AUC after review of the ASL images (AUC = 0.798 pre-ASL, AUC = 0.891 post-ASL; P = .02). Multivariate regression identified venous ASL signal intensity as the strongest predictor of positive findings on a DSA study, with an odds ratio of 17.3 (95% CI, 3.3-90.4).Identifying venous ASL signal intensity improved detection of DAVFs and small AVMs. Attention to this finding may improve triage to DSA in patients with suspected small vascular malformations.

Abstract

Since transient ischemic attacks (TIAs) can predict future stroke, it is important to distinguish true vascular events from non-vascular etiologies. Arterial spin labeling (ASL) is a non-contrast magnetic resonance (MR) method that is sensitive to cerebral perfusion and arterial arrival delays. Due to its high sensitivity to minor perfusion alterations, we hypothesized that ASL abnormalities would be identified frequently in TIA patients, and could therefore help increase clinicians' confidence in the diagnosis.We acquired diffusion-weighted imaging (DWI), intracranial MR angiography (MRA), and ASL in a prospective cohort of TIA patients. A subset of these patients also received bolus contrast perfusion-weighted imaging (PWI). Two neuroradiologists evaluated the images in a blinded fashion to determine the frequency of abnormalities on each imaging sequence. Kappa (?) statistics were used to assess agreement, and the ?(2) test was used to detect differences in the proportions of abnormal studies.76 patients met the inclusion criteria, 48 (63%) of whom received PWI. ASL was abnormal in 62%, a much higher frequency compared with DWI (24%) and intracranial MRA (13%). ASL significantly increased the MR imaging yield above the combined DWI and MRA yield (62 vs. 32%, p < 0.05). Arterial transit artifact in vascular borderzones was the most common ASL abnormality (present in 51%); other abnormalities included focal high or low ASL signal (11%). PWI was abnormal in 31% of patients, and in these, ASL was abnormal in 14 out of 15 cases (93%). In hemispheric TIA patients, both PWI and ASL findings were more common in the symptomatic hemisphere. Agreement between neuroradiologists regarding abnormal studies was good for ASL and PWI [? = 0.69 (95% CI 0.53-0.86) and ? = 0.66 (95% CI 0.43-0.89), respectively].In TIA patients, perfusion-related alterations on ASL were more frequently detected compared with PWI or intracranial MRA and were most frequently associated with the symptomatic hemisphere. Almost all cases with a PWI lesion also had an ASL lesion. These results suggest that ASL may aid in the workup and triage of TIA patients, particularly those who cannot undergo a contrast study.

Abstract

MRV has been proposed as a possible screening method to identify chronic cerebrospinal venous insufficiency, which may play a role in MS. We report our initial experience comparing MRV and CV in MS patients to evaluate venous stenosis and collateral venous drainage.Time-of-flight and time-resolved imaging of contrast kinetics MRV and CV were performed in 39 MS patients. The presence and severity of both IJ vein caliber changes and non-IJ collaterals were graded by using a 4-point scale by 2 radiologists in an independent and blinded manner.Both studies frequently showed venous abnormalities, most commonly IJ flattening at the C1 level and in the lower neck. There was moderate-to-good agreement between the modalities (? = 0.55; 95% CI, 0.45%-0.65%). For collaterals, agreement was only fair (? = 0.30; 95% CI, 0.09%-0.50%). The prevalence of IJ segments graded mild or worse on CV was 54%. If CV was considered a standard, the sensitivity and specificity of MRV was 0.79 (0.71-0.86) and 0.76 (0.67-0.83), respectively. Degree of stenosis was related to the severity of collaterals for CV but not for MRV.IJ caliber changes were seen in characteristic locations on both MRV and CV in MS patients. Agreement between modalities was higher for stenosis than for collaterals. If CV is considered a standard, MRV performance is good but may require additional improvement before MRV can be used for screening.

Abstract

Few studies have evaluated the use of intensity-modulated radiotherapy (IMRT) for squamous cell carcinoma (SCC) of the oral cavity (OC). We report clinical outcomes and failure patterns for these patients.Between October 2002 and June 2009, 37 patients with newly diagnosed SCC of the OC underwent postoperative (30) or definitive (7) IMRT. Twenty-five patients (66%) received systemic therapy. The median follow-up was 38 months (range, 10-87 months). The median interval from surgery to RT was 5.9 weeks (range, 2.1-10.7 weeks).Thirteen patients experienced local-regional failure at a median of 8.1 months (range, 2.4-31.9 months), and 2 additional patients experienced local recurrence between surgery and RT. Seven local failures occurred in-field (one with simultaneous nodal and distant disease) and two at the margin. Four regional failures occurred, two in-field and two out-of-field, one with synchronous metastases. Six patients experienced distant failure. The 3-year actuarial estimates of local control, local-regional control, freedom from distant metastasis, and overall survival were 67%, 53%, 81%, and 60% among postoperative patients, respectively, and 60%, 60%, 71%, and 57% among definitive patients. Four patients developed Grade ? 2 chronic toxicity. Increased surgery to RT interval predicted for decreased LRC (p = 0.04).Local-regional control for SCC of the OC treated with IMRT with or without surgery remains unsatisfactory. Definitive and postoperative IMRT have favorable toxicity profiles. A surgery-to-RT interval of < 6 weeks improves local-regional control. The predominant failure pattern was local, suggesting that both improvements in target delineation and radiosensitization and/or dose escalation are needed.

Abstract

Motion--both rigid-body and nonrigid--is the main limitation to in vivo, high-resolution larynx imaging. In this work, a new real-time motion compensation algorithm is introduced. Navigator data are processed in real time to compute the displacement information, and projections are corrected using phase modulation in k-space. Upon automatic feedback, the system immediately reacquires the data most heavily corrupted by nonrigid motion, i.e., the data whose corresponding projections could not be properly corrected. This algorithm overcomes the shortcomings of the so-called diminishing variance algorithm by combining it with navigator-based rigid-body motion correction. Because rigid-body motion correction is performed first, continual bulk motion no longer impedes nor prevents the convergence of the algorithm. Phantom experiments show that the algorithm properly corrects for translations and reacquires data corrupted by nonrigid motion. Larynx imaging was performed on healthy volunteers, and substantial reduction of motion artifacts caused by bulk shift, swallowing, and coughing was achieved.

Abstract

DWI of the spinal cord is challenging because of its small size and artifacts associated with the most commonly used clinical imaging method, SS-EPI. We evaluated the performance of rFOV spinal cord DWI and compared it with the routine fFOV SS-EPI in a clinical population.Thirty-six clinical patients underwent 1.5T MR imaging examination that included rFOV SS-EPI DWI of the cervical spinal cord as well as 2 comparison diffusion sequences: fFOV SS-EPI DWI normalized for either image readout time (low-resolution fFOV) or spatial resolution (high-resolution fFOV). ADC maps were created and compared between the methods by using single-factor analysis of variance. Two neuroradiologists blinded to sequence type rated the 3 DWI methods, based on susceptibility artifacts, perceived spatial resolution, signal intensity-to-noise ratio, anatomic detail, and clinical utility.ADC values for the rFOV and both fFOV sequences were not statistically different (rFOV: 1.01 ± 0.18 × 10(-3) mm(2)/s; low-resolution fFOV: 1.12 ± 0.22 × 10(-3) mm(2)/s; high-resolution fFOV: 1.10 ± 0.21 × 10(-3) mm(2)/s; F = 2.747, P > .05). The neuroradiologist reviewers rated the rFOV diffusion images superior in terms of all assessed measures (P < 0.0001). Particular improvements were noted in patients with metal hardware, degenerative disease, or both.rFOV DWI of the spinal cord overcomes many of the problems associated with conventional fFOV SS-EPI and is feasible in a clinical population. From a clinical standpoint, images were deemed superior to those created by using standard fFOV methods.

Abstract

We describe two cases of dural arteriovenous fistula (DAVF) developing in a delayed fashion after translabyrinthine resection of cerebellopontine angle tumors. Two patients in an academic tertiary referral center, a 46-year-old woman and a 67-year-old man, underwent translabyrinthine resection of a 2-cm left vestibular schwannoma and a 4-cm left petrous meningioma, respectively. Both patients subsequently developed DAVF, and in each case the diagnosis was delayed despite serial imaging follow-up. In one patient, cerebrospinal fluid diversion before DAVF was identified as the cause of her intracranial hypertension; the other patient was essentially asymptomatic but with a high risk of hemorrhage due to progression of cortical venous drainage. Endovascular treatment was effective but required multiple sessions due to residual or recurrent fistulas. Dural arteriovenous fistula is a rare complication of translabyrinthine skull base surgery. Diagnosis requires a high index of clinical suspicion and an understanding of subtle imaging findings that may be present on follow-up studies performed for tumor surveillance. Failure to recognize this complication may lead to misguided interventions for treatment of hydrocephalus and other complications, as well as ongoing risks related to venous hypertension and intracranial hemorrhage. As this condition is generally curable with neurointerventional and/or surgical methods, timely diagnosis and treatment are essential.

Association of venous malformation of the head and neck with meningoencephalocele: report of 3 cases.AJNR. American journal of neuroradiologySalehian, S., Fischbein, N. J.2011; 32 (4): E65-8

Abstract

Venous malformations have previously been reported to be associated with skeletal changes in humans, typically demineralization and localized deformation of the long bones. We report a presumed developmental association between venous malformations of the head and neck and meningoencephaloceles involving the sphenoid and temporal bones. Recognition of this association is important to avoid misinterpretation of these changes as a more aggressive process. We present the imaging findings and suggest an embryologic basis for this previously unreported association.

Abstract

The diagnosis of intracranial DAVF with noninvasive cross-sectional imaging such as CTA is challenging. We sought to determine the sensitivity and specificity of CTA compared with cerebral angiography for DAVF in patients presenting with PT.Following approval of the institutional review board, we reviewed all patients who underwent CTA for PT from 2004 to 2009 and collected clinical and imaging data. Seven patients with PT and proved DAVF and 7 age- and sex-matched control patients with PT but no DAVF composed the study group. CTA images were blindly interpreted by 2 experienced neuroradiologists for the presence of 5 variables: asymmetric arterial feeding vessels, "shaggy" appearance of a dural venous sinus, transcalvarial venous channels, asymmetric venous collaterals, and abnormal size and number of cortical veins. Asymmetric attenuation of jugular veins was additionally assessed.The presence of arterial feeders showed good test characteristics for screening, with a sensitivity of 86% (95% CI, 42-99) and a specificity of 100% (95% CI, 52-100). A shaggy sinus or tentorium was highly specific: sensitivity of 42% (95% CI, 11-79) and specificity of 100% (95% CI, 56-100). The presence of transcalvarial venous channels demonstrated a poor sensitivity of 29% (95% CI, 5-70) but a high specificity 86% (95% CI, 42-99). CT attenuation of the jugular veins showed statistically significant asymmetry in the DAVF group versus the control group (P < .05).CTA can be used to screen for DAVF in patients with PT. The presence of asymmetrically visible and enlarged arterial feeding vessels has a high sensitivity and specificity for the diagnosis of DAVF.

Abstract

BACKGROUND AND IMPORTANCE:: Papillary endothelial hyperplasia (PEH) is a rare form of exuberant reactive endothelial proliferation that can mimic neoplasm. We report the largest series of patients with histologically confirmed intracranial extravascular PEH developing in the field of prior treatment with stereotactic radiosurgery. CLINICAL PRESENTATION:: We collected the clinical, radiological, surgical, and pathologic findings in four cases of patients who developed intracranial extravascular PEH following treatment with stereotactic radiosurgery. In all cases the development of an enlarging hemorrhagic mass lesion in the site of prior radiotherapy on MRI was radiographically suspicious for neoplasm and prompted biopsy or resection. In all four cases the patients elected to undergo biopsy or surgical resection. Histologic examination of the biopsy and resection specimens in all cases demonstrated the classic features of PEH. CONCLUSION:: The interval to the development of PEH ranged from five months to six years and ten months. Clinical follow up was available for three of the four patients. None of these three patients has demonstrated evidence of recurrence during a mean follow-up period of 22 months (15-30 months). These cases share common radiological features, potentially allowing for pre-operative diagnosis and improved guidance of clinical management. These cases suggest a link between radiosurgery and the development of PEH. These findings also suggest that PEH should be considered in the differential diagnosis for patients treated with radiosurgery who subsequently develop a hemorrhagic mass lesion at or near the site of prior treatment. We think that complete surgical excision is the best treatment for intracranial PEH.

Abstract

Describe the first reported human intrathecal (IT) botulinum toxin injection.Case report.We report here the sequelae to an unintended IT injection of botulinum toxin type B (BTB) in a 60-year-old woman with chronic back pain.Following the IT administration of BTB, the patient experienced the onset of symmetric ascending stocking distribution painful dysesthesias, which persisted for approximately 6 months before receding. Objective neurologic deficits were not appreciated, and analgesic effects were prominently absent.Analgesic actions of botulinum toxins in animals and in humans have led to speculation that IT botulinum toxin might exert significant analgesic effects. The unusual and unexpected subsequent clinical course, neurologic sequelae, dysesthesias, and absence of analgesia suggest that botulinum toxin will not be a therapeutic modality to treat pain as proposed by those studying botulinum toxin in animal models.

Abstract

Nontraumatic (or spontaneous) intracranial hemorrhage most commonly involves the brain parenchyma and subarachnoid space. This entity accounts for at least 10% of strokes and is a leading cause of death and disability in adults. Important causes of spontaneous intracranial hemorrhage include hypertension, cerebral amyloid angiopathy, aneurysms, vascular malformations, and hemorrhagic infarcts (both venous and arterial). Imaging findings in common and less common causes of spontaneous intracranial hemorrhage are reviewed.

Abstract

Stenosis of a DVA may result in chronic venous ischemia. We present 6 patients (3 men, 3 women; age range, 30-79 years; mean age, 53 years) with unilateral calcification of the caudate and putamen on noncontrast CT. This calcification typically spared the anterior limb of the internal capsule. No patient presented with symptoms referable to the basal ganglia or had an underlying metabolic disorder or other process associated with calcium deposition. All patients subsequently underwent gadolinium-enhanced MR imaging and/or CTA or conventional angiography demonstrating the presence of an adjacent DVA. We hypothesize that chronic venous ischemia in the drainage territory of the DVA causes the abnormal mineralization. Greater recognition of this entity will prevent misinterpretation of this finding as acute hemorrhage and will prevent unnecessary and sometimes invasive evaluation in such patients. Furthermore, this entity should be considered in the differential diagnosis of unilateral basal ganglia hyperattenuation.

Abstract

Worldwide, an estimated 10 million people are affected annually by traumatic brain injury (TBI). More than 5 million Americans currently live with long-term disability as a result of TBI and more than 1.5 million individuals sustain a new TBI each year. It has been predicted that TBI will become the third leading cause of death and disability in the world by the year 2020. This article outlines the classification of TBI, details the types of lesions encountered, and discusses the various imaging modalities available for the evaluation of TBI.

Abstract

To study the incidence, pathogenesis, imaging characteristics, and clinical importance of a unique subtype of epidural hematoma (EDH) associated with blunt head trauma.This study was reviewed and approved by the hospital's Institutional Review Board and was compliant with HIPAA. Informed consent was waived. The investigation was a retrospective study of 200 patients with acute supratentorial EDH, defined as a biconvex, high-attenuating, extraaxial hematoma. A subgroup of 21 patients in whom the EDH was located at the anterior aspect of the middle cranial fossa was defined. Computed tomographic images and inpatient medical records of these 21 patients were evaluated for imaging characteristics of the EDH, presence or absence of associated fracture, presence or absence of midline shift and/or mass effect, additional intracranial injury, and hospital clinical course.Twenty-one (10.5%) of 200 traumatic EDHs localized to the anterior middle cranial fossa. All of these 21 anterior temporal EDHs were juxtaposed to the sphenoparietal sinus, and all but one were limited laterally by the sphenotemporal suture and medially by the orbital fissure; none extended above the lesser sphenoid wing. Maximum thickness was less than 1 cm in 13 (62%) of 21 and less than 2 cm in 20 (95%) of 21 patients. Isolated fractures of the greater sphenoid wing and ipsilateral zygomaticomaxillary fractures were present in 12 (57%) of 21 and nine (43%) of 21 patients, respectively. Concomitant intracranial injury was identified in 15 (71%) of 21 patients. Twenty (95%) of 21 lesions were present at the admission study, and all 21 were stable or smaller at follow-up imaging. No patient required neurosurgical intervention of their anterior temporal EDH.Acute EDHs isolated to the anterior aspect of the middle cranial fossa constitute a subgroup of traumatic EDHs with a benign natural history. It is postulated that they arise from venous bleeding due to disruption of the sphenoparietal sinus.

Abstract

We report the case of an 18-year-old woman with an intradural retroclival retrosellar glioneuronal heterotopion. At the time of surgery, a well circumscribed pale-tan mass was identified posterior to and distinct from the posterior pituitary. Pathologic examination showed disorganized, non-neoplastic glial tissue characteristic of glioneuronal heterotopia. To our knowledge, this is the first report of such a lesion in this location.

Abstract

Occlusion of the AOP results in a characteristic pattern of ischemia: bilateral paramedian thalamus with or without midbrain involvement. Although the classic imaging findings are often recognized, only a few small case series and isolated cases of AOP infarction have been reported. The purpose of this study was to characterize the complete imaging spectrum of AOP infarction on the basis of a large series of cases obtained from multiple institutions.Imaging and clinical data of 37 patients with AOP infarction from 2000 to 2009 were reviewed retrospectively. The primary imaging criterion for inclusion was an abnormal signal intensity on MR imaging and/or hypoattenuation on CT involving distinct arterial zones of the bilateral paramedian thalami with or without rostral midbrain involvement. Patients were excluded if there was a neoplastic, infectious, or inflammatory etiology.We identified 4 ischemic patterns of AOP infarction: 1) bilateral paramedian thalamic with midbrain (43%), 2) bilateral paramedian thalamic without midbrain (38%), 3) bilateral paramedian thalamic with anterior thalamus and midbrain (14%), and 4) bilateral paramedian thalamic with anterior thalamus without midbrain (5%). A previously unreported finding (the "V" sign) on FLAIR and DWI sequences was identified in 67% of cases of AOP infarction with midbrain involvement and supports the diagnosis when present.The 4 distinct patterns of ischemia identified in our large case series, along with the midbrain V sign, should improve recognition of AOP infarction and assist with the neurologic evaluation and management of patients with thalamic strokes.

Abstract

Diffusion-weighted magnetic resonance imaging of the brain is a promising technique to help predict functional outcome in comatose survivors of cardiac arrest. We aimed to evaluate prospectively the temporal-spatial profile of brain apparent diffusion coefficient changes in comatose survivors during the first 8 days after cardiac arrest.Apparent diffusion coefficient values were measured by 2 independent and blinded investigators in predefined brain regions in 18 good- and 15 poor-outcome patients with 38 brain magnetic resonance imaging scans and were compared with those of 14 normal controls. The same brain regions were also assessed qualitatively by 2 other independent and blinded investigators.In poor-outcome patients, cortical structures, in particular the occipital and temporal lobes, and the putamen exhibited the most profound apparent diffusion coefficient reductions, which were noted as early as 1.5 days and reached a nadir between 3 and 5 days after the arrest. Conversely, when compared with normal controls, good-outcome patients exhibited increased diffusivity, in particular in the hippocampus, temporal and occipital lobes, and corona radiata. By qualitative magnetic resonance imaging readings, 1 or more cortical gray matter structures were judged to be moderately to severely abnormal in all poor-outcome patients except for the 3 patients imaged within 24 hours after the arrest.Brain diffusion-weighted imaging changes in comatose, postcardiac arrest survivors in the first week after the arrest are region and time dependent and differ between good- and poor-outcome patients. With increasing use of magnetic resonance imaging in this context, it is important to be aware of these relations.

Abstract

Crossed cerebellar diaschisis (CCD) has been reported on positron-emission tomography and single-photon emission computed tomography of stroke patients. Rarely it has been described with brain diffusion-weighted MRI (DWI) of status epilepticus (SE).Case report.A 53-year-old woman was found unresponsive after cocaine use. A diagnostic electroencephalogram was consistent with ictal SE. A brain DWI showed reduced diffusion in the left temporo-parietal and occipital cortexes, the left thalamus and the right cerebellum. The DWI changes did not correspond to a vascular territory and were attributed to seizure activity and secondary CCD. A 2-week follow-up DWI showed interval near-complete resolution of the diffusion changes. CCD in SE may represent injury caused by excessive neuronal transmission from prolonged excitatory synaptic activity via the cortico-pontine-cerebellar pathway. Alternatively, it may be a result of interruption of the cortico-pontine-cerebellar pathway with loss of cortical inhibitory input.This case documents CCD during SE, providing further evidence of contralateral cerebellar involvement with a supratentorial epileptiform focus.

Abstract

Superficial siderosis (SS) of the central nervous system is a rare condition caused by chronic subarachnoid hemorrhage. Clinical manifestations typically include sensorineural hearing loss and cerebellar ataxia. Recurrent episodic encephalopathy in the setting of SS has not been reported. We describe a unique case of SS in a 67-year-old man with an 8-year history of episodic encephalopathy associated with headache and vomiting. The patient also had a history of progressive dementia, ataxia, and myelopathy. A diagnosis of superficial siderosis was made after magnetic resonance gradient-echo images showed diffuse hemosiderin staining over the cerebellum and cerebral convexities. No intracerebral source of hemorrhage was identified. The patient therefore underwent gadolinium-enhanced spinal MRI which suggested a possible vascular malformation. A therapeutic laminectomy subsequently confirmed an arteriovenous fistula which was resected. In SS, there are often long delays between symptom onset and definitive diagnosis. Early identification is facilitated by magnetic resonance imaging with gradient-echo sequences. When no source of hemorrhage is identified intracranially, then total spinal cord imaging is indicated to assess for an occult source of hemorrhage as occurred in our case.

Abstract

Inguinal hernia repair is associated with a high incidence of chronic postsurgical pain. This pain may be caused by injury to the iliohypogastric, ilioinguinal, or genitofemoral nerves. It is often difficult to identify the specific source of the pain, in part, because these nerves are derived from overlapping nerve roots and closely colocalize in the area of surgery. It is therefore technically difficult to selectively block these nerves individually proximal to the site of surgical injury. In particular, the genitofemoral nerve is retroperitoneal before entering the inguinal canal, a position that puts anterior approaches to the proximal nerve at risk of transgressing into the peritoneum. We report a computed tomography (CT)-guided transpsoas technique to selectively block the genitofemoral nerve for both diagnostic and therapeutic purposes while avoiding injury to the nearby ureter and intestines.A 39-year-old woman with chronic lancinating right groin pain after inguinal hernia repair underwent multiple pharmacologic interventions and invasive procedures without relief. Using CT and Stimuplex nerve stimulator guidance, the genitofemoral nerve was localized on the anterior surface of the psoas muscle and a diagnostic block with local anesthetic block was performed. The patient had immediate relief of her symptoms for 36 hours, confirming the diagnosis of genitofemoral neuralgia. She subsequently underwent CT-guided radiofrequency and phenol ablation of the genitofemoral nerve but has not achieved long-term analgesia.CT-guided transpsoas genitofemoral nerve block is a viable option for safely and selectively blocking the genitofemoral nerve for diagnostic or therapeutic purposes proximal to injury caused by inguinal surgery.

Abstract

The optimal diagnostic evaluation for spontaneous intracerebral hemorrhage (ICH) remains controversial. In this retrospective study, we assessed the utility of early magnetic resonance imaging (MRI) in ICH diagnosis and management.Eighty-nine (72%) of 123 patients with spontaneous ICH underwent a brain CT and MRI within 30 days of ICH onset. Seventy patients with a mean age of 62 ± 15 years were included. A stroke neurologist and a general neurologist, each blinded to the final diagnosis, independently reviewed the admission data and the initial head CT and then assigned a presumed ICH cause under 1 of 9 categories. ICH cause was potentially modified after subsequent MRI review. The final 'gold standard' ICH etiology was determined after review of the complete medical record by an independent investigator. Change in diagnostic category and confidence and the potential impact on patient management were systematically recorded.Mean time to MRI was 3 ± 5 days. Final ICH diagnosis was hypertension or cerebral amyloid angiopathy (CAA) in 50% of patients. After MRI review the stroke neurologist changed diagnostic category in 14%, diagnostic confidence in an additional 23% and management in 20%, and the general neurologist did so in 19, 21 and 21% of patients, respectively. MRI yield was highest in ICH secondary to ischemic stroke, CAA, vascular malformations and neoplasms, and did not differ by age, history of hypertension, hematoma location or the presence of intraventricular hemorrhage.The results of this study suggest potential additive clinical benefit of early MRI in patients with spontaneous ICH.

Abstract

The purpose of this series was to show the sonographic appearance of calcified cervical lymph nodes and the utility of sonographically guided fine-needle aspiration biopsy (FNAB) in the setting of metastatic squamous cell carcinoma (SCC).Two cases of confirmed metastatic SCC to cervical lymph nodes were identified. Sonography and sonographically guided FNAB were performed in both cases with positron emission tomography (PET)/computed tomography (CT) correlation.In case 1, sonography identified a diffusely calcified, avascular cervical lymph node. Positron emission tomography/CT suggested granulomatous disease as a cause for hypermetabolism; however, sonographically guided FNAB identified metastatic SCC. In the second case, FNAB initially performed without sonographic guidance did not show malignancy. Subsequent FNAB with sonographic guidance identified an abnormal cervical lymph node with focal calcifications and internal color Doppler flow. Metastatic SCC was diagnosed on histopathologic examination. Subsequent PET/CT confirmed multiple punctate calcifications in a hypermetabolic lymph node.Calcifications in cervical lymph nodes from metastatic SCC are very rare. These 2 cases show the variable sonographic appearances and the utility of sonographically guided FNAB in establishing the correct diagnosis.

Abstract

Although radiosurgery plays an important role in managing benign cranial base lesions, the potential for increased toxicity with single-session treatment of large tumors is a concern. In this retrospective study, we report the intermediate-term rate of local control, morbidity, and clinical outcomes of patients with large cranial base tumors treated with multisession stereotactic radiosurgery with the CyberKnife (Accuray, Inc., Sunnyvale, CA).Between 1999 and 2008, 34 consecutive patients with large (>15 cm), benign cranial base tumors (21 meningiomas, 9 schwannomas, 4 glomus jugulare tumors) underwent primary or postoperative radiosurgical treatment using a multisession approach at Stanford University and were considered in this retrospective study. Forty-four percent of these patients had undergone previous subtotal surgical resection or radiotherapy. CyberKnife radiosurgery was delivered in 2 to 5 sessions (median, 3 sessions) to a median tumor volume of 19.3 cm (range, 15.8-69.3 cm). The median marginal dose was 24 Gy (range, 18-25 Gy) prescribed to a median 78% isodose line.After a median clinical follow-up of 31 months (range, 12-77 months), 21% of patients experienced clinical improvement of neurological symptoms, whereas neurological status remained unchanged among the rest. Four patients experienced prolonged use of glucocorticoids owing to transient neurological worsening and radiographic signs of radiation injury. No permanent neurotoxicity was seen. To date, all tumors remain locally controlled.Over our modest length of follow-up, multisession radiosurgery appears to be a safe and effective option for selected large, benign brain and cranial base lesions.

Abstract

We present a case of congenital salivary gland anlage tumor (SGAT) of the nasal septum in a 2-week-old infant who had difficulty breathing through her nose since birth. CT and MR imaging demonstrated a circumscribed mass within the nasal cavity that did not communicate with the intracranial compartment. Differential diagnosis and clinical significance of recognizing this rare lesion are reviewed.

Abstract

Outcome prediction is challenging in comatose postcardiac arrest survivors. We assessed the feasibility and prognostic utility of brain diffusion-weighted magnetic resonance imaging (DWI) during the first week.Consecutive comatose postcardiac arrest patients were prospectively enrolled. AWI data of patients who met predefined specific prognostic criteria were used to determine distinguishing apparent diffusion coefficient (ADC) thresholds. Group 1 criteria were death at 6 months and absent motor response or absent pupillary reflexes or bilateral absent cortical responses at 72 hours or vegetative at 1 month. Group 2 criterion was survival at 6 months with a Glasgow Outcome Scale score of 4 or 5 (group 2A) or 3 (group 2B). The percentage of voxels below different ADC thresholds was calculated at 50 x 10(-6) mm(2)/sec intervals.Overall, 86% of patients underwent DWI. Fifty-one patients with 62 brain DWIs were included. Forty patients met the specific prognostic criteria. The percentage of brain volume with an ADC value less than 650 to 700 x 10(-6)mm(2)/sec best differentiated between Group 1 and Groups 2A and 2B combined (p < 0.001), whereas the 400 to 450 x 10(-6)mm(2)/sec threshold best differentiated between Groups 2A and 2B (p = 0.003). The ideal time window for prognostication using DWI was between 49 and 108 hours after the arrest. When comparing DWI in this time window with the 72-hour neurological examination, DWI improved the sensitivity for predicting poor outcome by 38% while maintaining 100% specificity (p = 0.021).Quantitative DWI in comatose postcardiac arrest survivors holds promise as a prognostic adjunct.

Abstract

The management of patients with trigeminal system dysfunction requires an understanding of the system's complex anatomy, which extends from peripheral nerve endings, through the skull base, cavernous sinus (V1, V2 only), and trigeminal ganglion, to the intraaxial nuclei, tracts, and cerebral cortex. The differential diagnosis is broad. Seemingly minor facial sensory loss may indicate an underlying malignancy (as in numb-chin syndrome). Painful syndromes of the trigeminal nerve are numerous and require careful categorization. Understanding trigeminal system anatomy and the appropriate use of imaging and electrodiagnostics should aid in the diagnosis and treatment of these disorders.

Abstract

Conventional angiography has been historically considered the gold standard for the diagnosis of cervical artery dissection, but MR imaging/MR angiography (MRA) and CT/CT angiography (CTA) are commonly used noninvasive alternatives. The goal of this study was to compare the ability of multidetector CT/CTA and MR imaging/MRA to detect common imaging findings of dissection.Patients in the data base of our Stroke Center between 2003 and 2007 with dissections who had CT/CTA and MR imaging/MRA on initial work-up were reviewed retrospectively. Two neuroradiologists evaluated the images for associated findings of dissection, including acute ischemic stroke, luminal narrowing, vessel irregularity, wall thickening/hematoma, pseudoaneurysm, and intimal flap. The readers also subjectively rated each vessel on the basis of whether the imaging findings were more clearly displayed with CT/CTA or MR imaging/MRA or were equally apparent.Eighteen patients with 25 dissected vessels (15 internal carotid arteries [ICA] and 10 vertebral arteries [VA]) met the inclusion criteria. CT/CTA identified more intimal flaps, pseudoaneurysms, and high-grade stenoses than MR imaging/MRA. CT/CTA was preferred for diagnosis in 13 vessels (5 ICA, 8 VA), whereas MR imaging/MRA was preferred in 1 vessel (ICA). The 2 techniques were deemed equal in the remaining 11 vessels (9 ICA, 2 VA). A significant preference for CT/CTA was noted for VA dissections (P < .05), but not for ICA dissections.Multidetector CT/CTA visualized more features of cervical artery dissection than MR imaging/MRA. CT/CTA was subjectively favored for vertebral dissection, whereas there was no technique preference for ICA dissection. In many cases, MR imaging/MRA provided complementary or confirmatory information, particularly given its better depiction of ischemic complications.

Abstract

To determine long-term outcomes in patients receiving stereotactic radiotherapy (SRT) as a boost after external beam radiotherapy (EBRT) for locally advanced nasopharyngeal carcinoma (NPC).Eight-two patients received an SRT boost after EBRT between September 1992 and July 2006. Nine patients had T1, 30 had T2, 12 had T3, and 31 had T4 tumors. Sixteen patients had Stage II, 19 had Stage III, and 47 had Stage IV disease. Patients received 66 Gy of EBRT followed by a single-fraction SRT boost of 7-15 Gy, delivered 2-6 weeks after EBRT. Seventy patients also received cisplatin-based chemotherapy delivered concurrently with and adjuvant to radiotherapy.At a median follow-up of 40.7 months (range, 6.5-144.2 months) for living patients, there was only 1 local failure in a patient with a T4 tumor. At 5 years, the freedom from local relapse rate was 98%, freedom from nodal relapse 83%, freedom from distant metastasis 68%, freedom from any relapse 67%, and overall survival 69%. Late toxicity included radiation-related retinopathy in 3, carotid aneurysm in 1, and radiographic temporal lobe necrosis in 10 patients, of whom 2 patients were symptomatic with seizures. Of 10 patients with temporal lobe necrosis, 9 had T4 tumors.Stereotactic radiotherapy boost after EBRT provides excellent local control for patients with NPC. Improved target delineation and dose homogeneity of radiation delivery for both EBRT and SRT is important to avoid long-term complications. Better systemic therapies for distant control are needed.

Abstract

The CT appearance of the anterior skull base has been investigated but with limited attention directed to the olfactory recess. As defined by opacity abutting the undersurface of the cribriform plate, the prevalence of olfactory recess opacity (ORO) on sinus CT was examined to clarify whether this should raise suspicion for an unsuspected pathologic process.Outpatient sinus CTs were evaluated for ORO in 500 consecutive patients (mean age, 46.9 years; 52.6% women). On a per-side basis (n = 1000), the presence of surgical changes, inflammatory sinus disease, and concha bullosa was determined by 2 neuroradiologists. Logistic regression was used to examine the association of ORO with these variables.ORO was identified in 59 (11.8%) patients, bilateral in 27 (5.4%), and unilateral in 32 (6.4%). There were 343 of 1000 ethmoid sides that were diseased, and 66 (27.2%) showed ipsilateral ORO. In contrast, only 20 (3.0%) of 657 clear ethmoid sides showed ORO (P < .0001). ORO was significantly (P = .013) more common with previous surgery (18/75; 24.0%) than without (68/925; 7.4%). Ipsilateral concha bullosa was not associated with ORO. Of 32 patients with unilateral ORO, 5 (15.6%) had no ethmoid opacification or previous surgery, and 1 of these patients had an encephalocele causing the ORO. Finally, unilateral ORO was present in only 1 of 122 patients with completely clear sinuses (the encephalocele that was just mentioned).ORO is distinctly uncommon without sinonasal inflammation or previous surgery. Isolated unilateral ORO raises suspicion for an underlying neoplasm or cephalocele and warrants further evaluation.

Abstract

The utility of 18-F-fluorodeoxyglucose-positron emission tomography (PET) and PET/CT for the evaluation of skull base tumors is incompletely investigated, as a limited number of studies specifically focus on this region with regard to PET imaging. Several patterns can be ascertained, however, by synthesizing the data from various published reports and cases of primary skull base malignancies, as well as head and neck malignancies that extend secondarily to the skull base, including nasopharyngeal carcinoma, nasal cavity and paranasal sinus tumors, parotid cancers, and orbital tumors.

Abstract

An otherwise healthy 12-month-old girl presented for evaluation of reduced abduction of the left eye detected at 6 months of age. The remainder of the examination was unremarkable. A special MRI sequence-fast imaging employing steady-state acquisition (FIESTA)-visualized the right but not the left sixth nerve cisternal segment. This is the first reported use of the MRI FIESTA sequence to diagnose aplasia of the sixth cranial nerve.

Abstract

18F-FDG PET/CT has rapidly become a widely used imaging modality for evaluating a variety of malignancies, including squamous cell carcinoma of the head and neck and thyroid cancer. Using both published data and the multidisciplinary experience at our institution, we provide a practical set of guidelines and algorithms for the use of 18F-FDG PET/CT in the evaluation and management of head and neck cancer and thyroid cancer.

Abstract

Sex influences outcome after intravenous thrombolysis. In a combined analysis of the tissue plasminogen activator clinical trials, a sex-by-treatment interaction was observed. We sought to confirm that observation in an independent data set.Data were from the Pro-Urokinase for Acute Cerebral Thromboembolism-2 (PROACT-2) trial. Baseline factors were compared by sex. The primary outcome was an assessment of a sex-by-treatment interaction term within a logistic regression model, using a modified Rankin Scale score

Abstract

The objectives of this prospective study were to assess the reproducibility of the measurements of the cochlea and lateral semicircular canal (LSCC) and to determine if abnormal measurements predict sensorineural hearing loss (SNHL).Two readers independently measured the cochlear height on coronal section and the LSCC bony island width on axial section on 109 temporal bone computed tomography scans; audiologic data on these patients were collected independently from medical records. Inter- and intrareader variability was evaluated using intraclass correlation coefficients (ICCs) based on a random-effects model. The positive and negative predictive values of abnormal measurement for hearing loss were determined.There was excellent inter- and intraobserver agreement for both measurements (ICC >80%). The average cochlear height was 5.1 mm (normal range, 4.4-5.9 mm) and average LSCC bony island width was 3.7 mm (normal range, 2.6-4.8 mm). Review of the original radiology reports demonstrated that both cochlear hypoplasia and LSSC dysplasia were overlooked in >50% of patients with both abnormal measurements and SNHL. Cochlear hypoplasia (< 4.4 mm) had a positive predictive value of 100% for SNHL, whereas cochlear hyperplasia and bony island dysplasia were less predictive.The measurements of coronal cochlear height and axial LSCC bony width have excellent reproducibility and identify bony labyrinth abnormalities missed by visual inspection alone. In addition, cochlear hypoplasia is highly predictive of SNHL. To reliably identify inner ear malformations, measurement of the cochlear height and LSCC bony island width, in addition to the vestibular aqueduct, should be routinely performed on all temporal bone studies.

Abstract

Abnormalities on diffusion-weighted images (DWIs) and fluid-attenuated inversion recovery (FLAIR) images are reported in Creutzfeldt-Jakob disease (CJD). To our knowledge, no large study has been conducted to determine the sensitivity and specificity of DWI and FLAIR imaging for diagnosing CJD.Two neuroradiologists, blinded to diagnosis, retrospectively evaluated DWI and FLAIR images from 40 patients with probable or definite CJD and 53 control subjects with other forms of dementia and rated the likelihood of CJD on the basis of the imaging findings.DWI and FLAIR imaging was 91% sensitive, 95% specific, and 94% accurate for CJD. Interrater reliability was high (kappa = 0.93). Sensitivity was higher for DWI than FLAIR imaging. Abnormalities involved cortex and deep gray matter (striatum and/or thalamus) in 68% of patients with CJD, cortex alone in 24%, and deep gray matter alone in 5%. The most typical and specific patterns were corresponding hyperintensity on both FLAIR images and DWIs confined to the gray matter in the cortex, striatum, medial and/or posterior thalamus, or a combination of these areas. Narrow-window soft-copy review of artifact-free DWIs and FLAIR images and recognition of the normal variation in cortical signal intensity proved critical for successful differentiation of CJD from other dementias.Because specific patterns of abnormality on DWI and FLAIR images are highly sensitive and specific for CJD, these sequences should be performed whenever CJD is suspected.

Abstract

To estimate the prevalence of "incidental" acoustic neuromas (ANs) in the population at large.An intracranial magnetic resonance imaging (MRI) database of 46 414 patients presenting to the University of California, San Francisco (UCSF), without known audiovestibular complaints was searched retrospectively from July 1995 to February 2003. Seventy percent of these MRIs included gadolinium, and none was specifically targeted through the internal auditory canal. A medical chart review of 688 patients with acoustic neuromas presenting to UCSF between 1980 and 1999 was searched for sex distribution.Tertiary care university medical center.Eight patients with incidental AN were discovered. This figure suggests that undiagnosed ANs may be present in at least 0.02% of the population. Three patients were found to have audiovestibular symptoms on inquiry after diagnosis. Audiometry revealed asymmetry at 4 kHz in only 3 of 7 patients, with an otherwise symmetric audiogram in the remaining patients. Tumor size in this population ranged from 3 to 28 mm. Incidental ANs were more common in men, but ANs were more common in women overall.The prevalence of incidental AN appears to be roughly 2 in 10,000 people. This figure indicates that AN may be less prevalent than suggested in previously reported temporal bone studies and more prevalent than suggested by epidemiologic studies.

Abstract

This article focuses on selected key anatomic considerations in anterior skull base surgery, briefly reviews common pathologies of the paranasal sinuses, and provides an overview of surgical approaches, complications, and results.

Abstract

Histopathologic evaluation remains the reference standard for diagnosis of glioma and classification of histologic subtypes, but is challenged by subjective criteria, tissue sampling error, and lack of specific tumor markers. Anatomic imaging is essential for surgical planning of gliomas but is limited by its nonspecificity and its inability to depict beyond morphologic aberrations. The purpose of our study was to investigate dynamic susceptibility contrast-enhanced (DSC) MR imaging characteristics of the two most common subtypes of low-grade infiltrating glioma: astrocytoma and oligodendroglioma. We hypothesized that tumor blood-volume measurements, derived from DSC MR imaging, would help differentiate the two on the basis of differences in tumor vascularity.We studied 25 consecutive patients with treatment-naive, histopathologically confirmed World Health Organization grade II astrocytoma (n = 11) or oligodendroglioma (n = 14). All patients underwent anatomic and DSC MR imaging immediately before surgical resection. Histologic confirmation was obtained in all patients. Anatomic MR images were analyzed for morphologic features, and DSC MR data were processed to yield quantitative cerebral blood volume (CBV) measurements.The maximum relative CBV (rCBV(max)) in tumor ranged from 0.48 to 1.34 (0.92 +/- 0.27, median +/- SD) in astrocytomas and from 1.29 to 9.24 (3.68 +/- 2.39) in oligodendrogliomas. The difference in median rCBV(max) between the two tumor types was significant (P < .0001).The tumor rCBV(max) measurements derived from DSC MR imaging were significantly higher in low-grade oligodendrogliomas than in astrocytomas. Our findings suggest that tumor rCBV(max) derived from DSC MR imaging can be used to distinguish between the two low-grade gliomas.

Abstract

When squamous cell carcinoma (SCC) involves the palatine tonsils, they are generally enlarged and demonstrate intermediate to high signal intensity on T2-weighted MR images and enhance after gadolinium administration. We have identified two patients with SCC of the tonsil where the affected tonsil has low signal intensity on T2-weighted MR images and is smaller than the contralateral normal tonsil. We present the "small, dark tonsil" as an alternative imaging presentation of SCC and a new sign to look for when evaluating the patient with metastatic lymphadenopathy from an unknown primary tumor.

Abstract

To develop a population-based three-dimensional lymph node target volume of the head and neck.The T2 weighted axial magnetic resonance imaging (MRI) images of 35 patients with known head and neck cancer were reviewed. An experienced head and neck radiologist marked each lymph node (LN) electronically. The images were distributed to one of 12 axial levels of the head and neck with each level representing a distinct portion of the neck based on external contours and the presence of anatomic structures. The LNs were marked with five different symbols to distinguish the superior/inferior extent of each LN within each level. With the categorization of each image into a different superior/inferior level of the neck, the registration of the images was limited to two dimensions. Nonlinear transformation accounted for inter-patient differences although no local warping was used. The co-registration used recognizable anatomic landmarks (vertebral body, mandible, maxilla, clivus as well as the sternocleidomastoid muscle, external skin contour, spinal cord) to match the patient anatomy.In total, 503 images were co-registered with the baseline images. The majority of the co-registrations were of good quality; 361, 122, and 20 image co-registrations scored as global, limited, and poor co-registrations respectively. One thousand and fifty seven LNs were marked, with 122 LNs marked as submandibular and submental LN. Among the levels A, B, C, D, E, F, G, H, 22, 44, 206, 199, 196, 175, 63, 35 LN were marked respectively. Noteworthy anatomic variation was observed among the different nodal groups that are summarized in the representative baseline images.Image registration of a series of head and neck images generates a valuable population-based lymph node map that can be used to guide the three-dimensional delineation of the elective lymph node target volume. Significant variation in the lymph node location was seen in all LN groups. The medial border of the internal jugular vein can be used as an important landmark structure in delineating the jugular LN clinical target volume and, for that reason, intravenous contrast is recommended to improve visualization. The location of the submandibular LN appear to be limited to the space anterior and lateral to the submandibular gland and are found mostly along the inferior edge of the mandible. The location of the retropharyngeal LN does vary but their location does not appear to vary with any other recognizable axial structure. The lymph node map provides another collaborating piece of evidence in defining the head and neck LN clinical target volume.

Abstract

Collateral flow plays an important role in maintaining tissue viability in proximal large vessel occlusion. We developed and tested a regional angiographic collateral grading system for patients with angiographically confirmed acute symptomatic middle cerebral artery occlusion to predict regional infarction.A subset of 42 patients was selected from 180 patients enrolled in the Prolyse in Acute Cerebral Thromboembolism II (PROACT II) trial. Readers evaluated baseline cerebral angiograms in a blinded fashion for the degree of regional collateral circulation, which was graded on a 4-point scale in each of 15 anatomic regions. Regional and total collateral flow scores were compared with the presence or absence of infarction on 7- to 10-day follow-up computed tomography (CT), as well as clinical outcome as assessed by National Institute of Health Stroke Scale (NIHSS) scores.The collateral flow score on baseline angiography accurately predicted infarction, demonstrating a receiver operating characteristic curve of 0.87 (95% CI: 0.83 to 0.91) for all regions. Collateral grades on baseline angiography correlated moderately with infarct volume on follow-up CT scan at 7 to 10 days (R=0.61; P=0.0001). Collateral grades also correlated with follow-up NIHSS scores for patients who received thrombolysis (R=0.36 to 0.49, P<0.05), but not for control patients.An angiographic grading system for regional collateral flow accurately predicts the extent and location of cerebral infarction. This study corroborates the correlation between the presence of collateral flow, infarction volume, and clinical outcome, and it reinforces the need to control for collateral flow in clinical trials.

Abstract

A 75-year-old Asian man presented with two episodes of chorea associated with nonketotic hyperglycemia. His chorea rapidly resolved after restitution of a normal serum glucose level, although an MR image obtained at the time of acute symptoms demonstrated high signal intensity on T1-weighted images, low signal intensity on T2-weighted images, and restricted diffusion, all involving the left putamen. A CT scan obtained 1 month later demonstrated faint hyperattenuation of the involved putamen. The reported pathophysiologic considerations for these imaging features are reviewed, and an original explanation is proposed.

Abstract

Dynamic contrast-enhanced magnetic resonance imaging is a useful clinical tool in evaluation of soft tissue neoplasm and lymph nodes in head and neck. It is thought to be a useful predictor of response to radiotherapy for head and neck carcinoma and used to monitor the treatment and distinguish post-therapeutic changes from recurrent mass with greater confidence. It can be used to distinguish between normal and malignant tissue and to differentiate a malignant lymphoma from other lymph nodal enlargements. The technique utilizes relative differences in microvasculature and microcirculation between malignant and non-malignant tissue to achieve greater contrast in signal imaging following bolus contrast administration. This article explains the underlying principles and imaging techniques for this new diagnostic tool. The clinical applications and technical challenges are discussed. The future challenges and some contradictions in results are also outlined.

Abstract

Extension of malignant melanoma along cranial nerves is a little-known complication of malignant melanoma of the head and neck. We describe the clinical and MR imaging findings of perineural spread of malignant melanoma to cranial nerves, emphasizing that this entity occurs more commonly with desmoplastic histology and may have a long latent period following primary diagnosis.At two institutions, we identified and retrospectively reviewed eight cases of malignant melanoma of the head and neck that had MR imaging evidence of perineural spread of disease. All patients underwent confirmatory tissue sampling.Seven patients had melanomas of the facial skin or lip, and one patient had a primary sinonasal lesion. By histopathology, these melanomas included five desmoplastic, two mucosal, and one poorly differentiated melanotic spindle-cell tumor. All patients developed symptomatic cranial neuropathy an average of 4.9 years from the time of initial diagnosis. MR imaging demonstrated postgadolinium enhancement of at least one branch of the trigeminal nerve in all cases and of at least one other cranial nerve in five cases. Other findings included abnormal contrast enhancement and soft tissue thickening in the cavernous sinus, Meckel's cave, and/or the cisternal segment of the trigeminal nerve.Although perineural spread of disease occurs most commonly with squamous cell carcinoma and adenoid cystic carcinoma, malignant melanoma must also be included in this differential diagnosis, particularly if the patient's pathology is known to be desmoplastic. Similarly, any patient with malignant melanoma of the head and neck who undergoes MR imaging should receive an imaging assessment focused on the likely routes of perineural spread.

Abstract

In patients with congenital sensorineural hearing loss (SNHL), a computed tomography (CT) scan of the temporal bone identifies inner ear malformations in approximately 25%, whereas the inner ear is grossly normal to visual inspection in the remaining 75% of the patients. In the latter group, the hearing loss is often attributed to radiologically undetectable abnormalities of the membranous labyrinth. However, subtle bony malformations may be missed because visual inspection alone is insensitive for detection.To test the hypothesis that there are subtle bony abnormalities of the inner ear in patients with SNHL who are radiologically deemed to have normal otic bone, using standardized measurements of the inner ear.Retrospective review.Measurements of the cochlea, vestibule, and semicircular canals (SCCs) were made on axial and coronal temporal bone CT scans on 15 patients with normal hearing and 15 patients with congenital SNHL and grossly normal temporal bone CT scans. Student's t-test was performed to compare the measurements of the two groups. RESULTS All studies from the SNHL group were deemed normal by visual inspection and standardized measurements (+/-2 SD from normal). Surprisingly, there were significant differences in the measurements of the cochlea and of the SCCs between patients with and without SHNL (P

Abstract

To review the University of California-San Francisco (UCSF) experience of using intensity-modulated radiation therapy (IMRT) to treat head-and-neck cancer focusing on the importance of target volume delineation and adequate target volume coverage.Between April 1995 and January 2002, 150 histologically confirmed patients underwent IMRT for their head-and-neck cancer at our institution. Sites included were nasopharynx 86, oropharynx 22, paranasal sinus 22, thyroid 6, oral tongue 3, nasal cavity 2, salivary 2, larynx 2, hypopharynx 1, lacrimal gland 1, skin 1, temporal bone 1, and trachea 1. One hundred seven patients were treated definitively with IMRT +/- concurrent platinum chemotherapy (92/107), whereas 43 patients underwent gross surgical resection followed by postoperative IMRT +/- concurrent platinum chemotherapy (15/43). IMRT was delivered using three different techniques: 1) manually cut partial transmission blocks, 2) computer-controlled auto-sequencing segmental multileaf collimator, and 3) sequential tomotherapy using dynamic multivane intensity-modulating collimator. Forty-two patients were treated with a forward plan, 102 patients with an inverse plan, and 6 patients with both forward and inverse plans. The gross target volume (GTV) was defined as tumor detected on physical examination or imaging studies. In postoperative cases, the GTV was defined as the preoperative gross tumor volume. The clinical target volume (CTV) included all potential areas at risk for microscopic tumor involvement by either direct extension or nodal spread including a margin for patient motion and setup errors. The average prescription doses to the GTV were 70 Gy and 66 Gy for the primary and the postoperative cases, respectively. The site of recurrence was determined by the diagnostic neuroradiologist to be either within the GTV or the CTV volume by comparison of the treatment planning computed tomography with posttreatment imaging studies.For the primary definitive cases with a median follow-up of 25 months (range 6 to 78 months), 4 patients failed in the GTV. The 2- and 3-year local freedom from progression (LFFP) rates were 97% and 95%. With a median follow-up of 17 months (range 8 to 56 months), 7 patients failed in the postoperative setting. The 2-year LFFP rate was 83%. For the primary group, the average maximum, mean, and minimum doses delivered were 80 Gy, 74 Gy, 56 Gy to the GTV, and 80 Gy, 69 Gy, 33 Gy to the CTV. An average of only 3% of the GTV and 3% of the CTV received less than 95% of the prescribed dose. For the postoperative group, the average maximum, mean, and minimum doses delivered were 79 Gy, 71 Gy, 37 Gy to the GTV and 79 Gy, 66 Gy, 21 Gy to the CTV. An average of only 6% of the GTV and 6% of the CTV received less than 95% of the prescribed dose.Accurate target volume delineation in IMRT treatment for head-and-neck cancer is essential. Our multidisciplinary approach in target volume definition resulted in few recurrences with excellent LFFP rates and no marginal failures. Higher treatment failure rates were noted in the postoperative setting in which lower doses were prescribed. Potential dose escalation studies may further improve the local control rates in the postoperative setting.

Abstract

Anomalies of the course of the facial nerve have been reported in association with middle and inner ear malformations. Bifurcation of its intratemporal portion is a rare malformation in which focal splitting of one or more facial nerve segments occurs. We describe the CT appearance of this anomaly and discuss its possible embryology. Facial nerve bifurcation is important to recognize in patients undergoing evaluation for congenital hearing loss and other congenital ear malformations.

Abstract

Previous studies have suggested that baseline computed tomographic (CT) scans might be a useful tool for selecting particular ischemic stroke patients who would benefit from thrombolysis. The aim of the present study was to assess whether the baseline CT scan, assessed with the Alberta Stroke Program Early CT Score (ASPECTS), could identify ischemic stroke patients who might particularly benefit from intra-arterial thrombolysis of middle cerebral artery occlusion.Baseline and 24-hour follow-up CT scans of patients randomized within 6 hours of symptoms to intra-arterial thrombolysis with recombinant pro-urokinase or control in the PROACT-II study were retrospectively scored by using ASPECTS. Patients were stratified into those with ASPECTS >7 or < or =7. Independent functional outcome at 90 days was compared between the 2 strata according to treatment assignment.The analysis included 154 patients with angiographically confirmed middle cerebral artery occlusion. The unadjusted risk ratio of an independent functional outcome, in favor of treatment, in the ASPECTS >7 group was 5.0 (95% confidence interval [CI], 1.3 to 19.2) compared with 1.0 (95% CI, 0.6 to 1.9) in the ASPECTS < or =7 group. After adjustment for baseline characteristics, the risk ratio in the ASPECTS score >7 was 3.2 (95% CI, 1.2 to 9.1). Similar favorable treatment effects were observed when secondary outcomes were used, but these did not reach statistical significance.Ischemic stroke patients with a baseline ASPECTS >7 were 3 times more likely to have an independent functional outcome with thrombolytic treatment compared with control. Patients with a baseline ASPECTS < or =7 were less likely to benefit from treatment. This observation suggests that ASPECTS can be both a useful clinical tool and an important method of baseline risk stratification in future clinical trials of acute stroke therapy.

Abstract

Dynamic and functional imaging techniques are being developed to improve the evaluation of various pathologic processes of the head and neck region. These techniques include dynamic contrast-enhanced MR imaging for evaluating soft tissue masses and cervical lymph nodes, the use of ultrasmall superparamagnetic iron oxide contrast agent, and functional techniques such as in vivo and in vitro MR spectroscopy of head and neck cancer and lymph nodes and apparent diffusion coefficient mapping of parotid glands. These techniques can help to differentiate nonmalignant tissue from malignant tumors and lymph nodes and can aid in differentiating residual malignancies from postradiation changes. From methodological development, they are making the critical transition to preclinical and clinical validating methods and eventually to widespread clinical tools.

Abstract

Skull base osteomyelitis typically arises as a complication of ear infection in older diabetic patients, involves the temporal bone, and has Pseudomonas aeruginosa as the usual pathogen. Atypical skull base osteomyelitis arising from the sphenoid or occipital bones without associated external otitis occurs much less frequently and initially may have headache as the only symptom. The purpose of this study was to review the clinical and MR imaging features of central skull base osteomyelitis.We retrospectively reviewed MR images obtained in six patients with central skull base osteomyelitis. No patient had predisposing external otitis or osteomyelitis of the temporal bone.All of our patients presented with headache, no external ear pain, and cranial nerve deficits. Five of six patients had a predisposition to infection, and the erythrocyte sedimentation rate was elevated in the five patients in whom it was checked. In each case, the diagnosis was delayed until MR imaging demonstrated central skull base abnormality, and the diagnosis was then confirmed with tissue sampling. The most consistent imaging findings were clival bone marrow T1 hypointensity and preclival soft tissue infiltration. Five of six patients were cured with no recurrence of skull base infection over a 2-4-year follow-up period.In the setting of headache, cranial neuropathy, elevated erythrocyte sedimentation rate, and abnormal clival imaging findings, central skull base osteomyelitis should be considered as the likely diagnosis. Early tissue sampling and appropriate treatment may prevent or limit further complications such as intracranial extension, empyema, or death.

Abstract

Recent developments have made available for ophthalmologic MR imaging a very high-resolution 3D fast spin echo T2 (3D FSE T2) sequence, which runs in a standard head coil. A modification of this technique, 3D FSEz T2, uses a zero-filled slice interpolation method during post-processing to further improve spatial resolution. We describe the technique and share our early clinical observations in patients with ocular masses. Briefly, the additional information from the 3D FSEz T2 resulted in a change in diagnosis from the conventional imaging series in 11 of (41%) 27 studies, usually through the identification of previously treated retinoblastoma lesions. The new sequence significantly increased diagnostic confidence in six (38%) of the remaining 16 cases, usually through better anatomical detail and lesion conspicuity, and did not change interpretation in 10 cases. Such an approach improves diagnostic confidence and may eliminate the need for a dedicated surface coil examination.

Abstract

Spinal intradural arachnoid cysts are rare outpouchings of arachnoid lining occurring mainly in the thoracic and cervical regions. MRI is considered the diagnostic procedure of choice; however, some arachnoid cysts have been reported to elude diagnosis by MRI due to the similar signal intensity of the cyst and the subarachnoid space.We present a case of a 41-year-old woman with an intradural arachnoid cyst of the lumbar spinal canal. Diagnostic studies demonstrated a herniated L4-5 disk, which led to two operations. Despite intractable pain postoperatively, the MRI failed to reveal further focal compression of the nerve root. A myelogram suggested compression of the thecal sac by a dorsal mass lesion. The patient underwent a midline durotomy that revealed two large arachnoid cysts with the nerve roots beneath them pushed ventrally and to the right. Removal of the arachnoid layer resulted in complete fenestration of the cyst and allowed the nerve roots to freely float in the spinal fluid.In retrospect, the abnormality could be appreciated on multiple prior scans performed at another institution, demonstrating that in the patient with low back pain, degenerative disc disease is not the only diagnosis to consider.

Abstract

Trigeminal neuralgia is often the result of vascular compression at the root entry zone of the trigeminal nerve. We report a case of trigeminal neuralgia in a patient with a dural arteriovenous fistula in Meckel's cave. Endovascular closure of the fistula resulted in elimination of the patient's pain at the gasserian ganglion level.A 77-year-old woman was referred for treatment of trigeminal neuralgia after failed conservative treatment, including multiple gasserian ganglion blocks. Magnetic resonance imaging of the brain suggested a vascular lesion, and cerebral angiography demonstrated a dural arteriovenous fistula in Meckel's cave.Endovascular coil embolization was performed, with obliteration of the dural arteriovenous fistula and resolution of facial pain but with decreased sensation in the face.Trigeminal neuralgia may be associated with complex vascular lesions around the base of the brain and along the course of the trigeminal nerve. The evaluation of patients with trigeminal neuralgia should include high-quality, thin-section, magnetic resonance imaging scans, to exclude the possibility of vascular lesions and other structural lesions. In particular, patients who are being evaluated for surgical treatment of trigeminal neuralgia should undergo magnetic resonance imaging, with a focus on the course of the trigeminal nerve.

Abstract

To identify and overcome challenges in using dynamic contrast-enhanced magnetic resonance imaging (MRI) to distinguish tumor from nontumor in the cervical lymph nodes of patients with squamous cell carcinoma of the head and neck.Signal-to-noise ratio (S/N), motion, node heterogeneity, and tissue normalizations were examined. Twenty-one patients with squamous cell carcinoma of the head and neck were scanned before a neck dissection (two-dimensional fast spoiled gradient-echo: 10 locations/13 seconds). Peak time, peak enhancement, maximum upslope, and washout slope were measured in pathologically confirmed tumor and nontumor nodes and in the submandibular gland and the sternocleidomastoid muscle.Surface coil arrays provided high coverage and high S/N. Motion averaged 1.1 pixels and was corrected. Large tumor nodes were heterogeneous in their contrast enhancement, while the nontumor nodes were homogeneous. The contrast enhancement parameters were significantly different for all regions except for the submandibular gland compared to the nontumor nodes.Challenges of dynamic imaging of cervical lymph nodes were overcome and significant differences were found between the tumor and nontumor nodes, indicating that dynamic imaging is feasible and may aid this patient population.

Abstract

Morphologic assessment by conventional imaging methods of lymph node metastases in patients with squamous cell carcinoma of the head and neck is, at best, insensitive. Doppler sonography has shown that lymph node metastases exhibit alterations in the number of vessels and blood flow. We assessed the ability of dynamic contrast-enhanced MR imaging to differentiate normal from diseased nodes in this patient population.Twenty-one patients with newly diagnosed squamous cell carcinoma and no previous treatment were studied with the use of a head and neck phased array surface coil. Anatomic imaging included high resolution T1-weighted, fat-saturated fast spin-echo T2-weighted, and contrast-enhanced T1-weighted imaging (0.99-1.32 mm(3) voxels). The dynamic contrast-enhanced MR imaging was performed by using a 2D fast spoiled gradient recalled sequence with single dose bolus injection of contrast agent. Calculated values included time to peak, peak enhancement, maximum slope, and washout slope for the enhancement. All patients underwent neck dissection as part of their indicated treatment, and imaging results were correlated with pathologic findings.Dynamic contrast-enhanced MR imaging and pathology comparisons were obtained for 68 nodes. There was significantly longer time to peak (P

Abstract

We sought to establish normative measurements of the inner ear using computed tomography (CT) of the temporal bone to aid in the diagnosis of inner ear malformations.Prospective measurements of the inner ear structures were made on axial and coronal temporal bone CT scans on 15 patients with normal hearing and 15 patients with sensorineural hearing loss.The vertical height of the cochlea on coronal scan and the size of the central bony island within the lateral semicircular canal on axial scan along with visual inspection identified 7 inner ear abnormalities in 6 patients: 5 cases of lateral semicircular canal dysplasia and 2 cases of cochlear hypoplasia. In contrast, visual inspection alone identified only 4 of the 7 abnormalities.Routine measurement of the cochlear height and bony island of the lateral semicircular canal, in conjunction with visual inspection of CT images, will increase recognition of common inner ear malformations.

Abstract

Intracranial lipomas are uncommon congenital malformations that most often are asymptomatic. A rare subset of intracranial lipomas arises within the vestibule of the inner ear, which can cause sensorineural hearing loss. We present the CT and MR imaging characteristics of lipomas within the vestibule of the inner ear and propose a pathogenetic mechanism for this malformation.We retrospectively reviewed five cases of vestibular lipoma. T1-weighted axial conventional spin-echo and T2-weighted axial fast spin-echo sequences were performed in all five cases. Four patients underwent T1-weighted fat-saturated imaging, and one underwent CT scanning with Hounsfield units measured.Four female patients ranging in age from 10 to 40 years and one 26-year-old male patient had sensorineural hearing loss. Two patients had progressive high-frequency loss; one, sudden-onset high-frequency loss; and two, congenital high-frequency loss. All had lesions within the vestibule that displayed hyperintensity on T1-weighted images, isointensity to slight hypointensity on T2-weighted fast spin-echo images, hypointensity with fat saturation, and fat attenuation on CT scans. Three of the cases were associated with lipoma of the cerebellopontine angle. In none of these cases were the cerebellopontine angle and labyrinthine lipomas contiguous.Intravestibular lipoma is considered when a focal hyperintense lesion is identified within the vestibule of the inner ear on T1-weighted MR images. Lesion hypointensity on fat-saturated T1-weighted MR images verifies its lipomatous nature and separates it from intralabyrinthine hemorrhage or highly proteinaceous fluid.

Abstract

Ultrathin-section 3-dimensional fast spin-echo (3-D FSE) T2-weighted imaging is a new magnetic resonance imaging (MRI) technique that we used in the evaluation of ocular and orbital malignancies. We evaluated the usefulness of this new technique compared with conventional MRI.Imaging data from 26 consecutive patients seen in the Ocular Oncology Unit at the University of California-San Francisco were retrospectively reviewed by physicians from the ocular oncology and neuroradiology units. For all patients, 3-D FSE T2-weighted images (27 scans) were compared with results of conventional MRI and correlated with results of computed tomography (CT), A- and B-scan ultrasonography, ultrasound biomicroscopy, clinical examinations, and histopathology, when available.The 3-D FSE T2-weighted imaging sequence resulted in an overall improvement in accuracy of imaging findings in 17 (63%) of our 27 cases compared with the standard MRI protocol. The increased resolution led to the radiographic detection of additional lesions in 11 (41%) of 27 cases and to an increase in confidence in radiographic diagnosis in 6 (22%) of the remaining cases. The improved resolution of the 3-D FSE T2-weighted sequence resulted in a change of disease management in 3 (60%) of the 5 patients with nonretinoblastoma lesions. One hundred percent of active retinoblastoma lesions could be detected by means of 3-D FSE and conventional imaging; however, inactive lesions were not always detected using conventional imaging.The 3-D FSE T2-weighted sequence offers superior resolution of intraocular and orbital structures compared with conventional MRI. It is particularly useful in the evaluation of intraocular tumors and the nerve-sheath complex. This new technique contributes significantly to improved diagnosis and management in patients with ocular and orbital malignancies.

Abstract

The purpose of this study was to evaluate the role of noncontrast CT in the selection of patients to receive thrombolytic therapy for acute ischemic stroke and to predict radiological and clinical outcomes.One hundred eighty patients with stroke due to middle cerebral artery (MCA) occlusion were randomized 2:1 within 6 hours of onset to receive intra-arterial recombinant prourokinase plus intravenous heparin or intravenous heparin only. Four hundred fifty-four CT examinations were digitized to calculate early infarct changes, infarct volumes, and hemorrhagic changes among the 162 patients treated as randomized (108 recombinant prourokinase-treated patients and 54 control patients). CT changes were correlated with baseline stroke severity, angiographic clot location, collateral vessels, and outcome at 90 days.Baseline CT scans, 120 (75%) of 159, showed early infarct-related abnormalities. The baseline CT abnormality volume was not correlated with the baseline National Institutes of Health Stroke Scale (NIHSS) score (r=-0.11) but was correlated weakly with the outcome (r=0.17, P<0.05). Compared with patients with M2 occlusions, patients with M1 MCA occlusions had significantly higher baseline NIHSS scores (P<0.05), more basal ganglia involvement on CT, and larger hypodensity volumes on follow-up CTs. Compared with patients with partial or no collateral supply, patients with full collateral supply had lower baseline NIHSS scores, significantly smaller baseline CT infarct volumes, and less cortical involvement (P<0.05).Noncontrast CT is not correlated with baseline stroke severity and does not predict outcome in patients with stroke due to MCA occlusion. However, baseline CT changes, clinical presentation, and the evolution of CT changes are influenced by clot location and the presence of a collateral supply.

Abstract

Hemorrhage at presentation in primary CNS lymphoma is exceedingly rare. We describe a patient with primary CNS lymphoma who presented with seizures and was found to have an intracerebral hemorrhage which prompted a cerebral angiogram. Ultimately pathologic evaluation of the lesion revealed a highly cellular B-cell lymphoma with marked hypervascularity and intense expression of vascular endothelial growth factor (VEGF). A review of four other recent cases of primary CNS lymphoma at our institution revealed less-intense VEGF immunoreactivity. This is the first report of VEGF expression in primary CNS lymphoma. The potential significance of VEGF expression with respect to the biology of this tumor is discussed.

Abstract

Gadolinium-enhanced magnetic resonance imaging (GdMRI) is routinely used in the evaluation and management of suspected retrocochlear pathology such as vestibular schwannoma. However, its value in the evaluation and diagnosis of cochlear pathology associated with sensorineural hearing loss (SNHL) has been less clear.Retrospective review of case histories and imaging studies of patients with SNHL and cochlear enhancement on GdMRI diagnosed between 1998 and 2000.Five patients with SNHL who required gadolinium administration to establish the diagnosis of endocochlear disease were identified. Diagnosed lesions included an intralabyrinthine schwannoma, intracochlear hemorrhage, radiation-induced ischemic change, autoimmune labyrinthitis, and meningogenic labyrinthitis. In these illustrative cases, the GdMRI demonstrated intrinsic high signal or contrast enhancement within the cochlea and labyrinth in the absence of a retrocochlear mass. In one patient with meningogenic labyrinthitis, cochlear enhancement on MRI led to prompt cochlear implantation before the potential development of cochlear ossification.Our experience suggests that GdMRI plays a crucial role in the diagnosis of cochlear pathology associated with sensorineural hearing loss and may directly impact patient management.

Abstract

Petrous apex cephaloceles (PACs) are uncommon lesions that are usually incidental but may be symptomatic. We reviewed MR and CT studies in 10 patients with PACs to identify characteristic imaging features that facilitate their diagnosis.MR and CT studies from 10 patients with PACs were reviewed retrospectively. In each case the PAC was characterized by lesion center, signal intensity or attenuation, adjacent petrous apex pneumatization, and its relationship to Meckel's cave. Intraoperative findings were reviewed in the three cases in which surgery was performed.All 10 patients had lobulated expansile cystic petrous apex lesions centered along the posterolateral margin of Meckel's cave. All cysts were contiguous with Meckel's cave. Three patients had bilateral PACs. Four patients had symptoms that could potentially be explained by the PAC, while findings in the other six were incidental observations. Three patients underwent surgery, during which two lesions were diagnosed as meningoceles while the third was diagnosed as an arachnoid cyst protruding through a dural defect.PACs represent a protrusion of meninges and CSF from the posterolateral portion of Meckel's cave into the petrous apex, which is their characteristic imaging appearance. PACs are usually incidental but may be symptomatic. Surgical intervention should be approached cautiously and undertaken only when symptoms are clearly linked to the presence of this lesion.

Abstract

The purpose of this study was to develop coils for MR imaging of the head and neck region, with the aim of improving sensitivity and coverage. A head and neck phased array coil was constructed and compared with volume and temporomandibular joint surface coils for sensitivity and coverage in phantom studies. An algorithm was implemented to correct for the nonuniformity in the surface coil reception profile. Its application to high-resolution T2-weighted imaging in healthy volunteers was investigated.

Abstract

Spontaneous retropharyngeal hematoma is an uncommon entity that is difficult to diagnose and may progress rapidly to airway obstruction. We report a case of a 53-year-old man with acute onset of retropharyngeal pain, dysphonia, and dysphagia after vomiting. On CT, a nonspecific retropharyngeal collection was seen. MR imaging demonstrated blood products, suggesting a diagnosis of retropharyngeal hematoma, and the patient was managed conservatively. MR imaging allowed specific diagnosis of a rare condition that is otherwise difficult to diagnose without surgical intervention.

Abstract

A new CT perfusion technique providing extended anatomic coverage was evaluated in 12 patients with suspected acute middle cerebral artery ischemia. With a multidetector CT scanner, scans were obtained in an alternating fashion at two distinct "toggling" table positions (two 1-cm sections each) during a 40-mL contrast agent bolus (approximately 5 seconds per image), and perfusion parameter maps were created. The CT perfusion results were compared with follow-up images. Nine patients showed focal perfusion abnormalities in at least one section, most commonly on mean transit time maps. Using a single table location would have underestimated or missed the involved tissue in most cases. In three of 12 patients, perfusion maps failed to delineate any abnormality. In two patients, perfusion and diffusion MR imaging confirmed the absence of perfusion abnormality and tissue injury, respectively. In one case, a small ischemic injury was revealed by diffusion MR imaging. By using the toggling-table approach, perfusion images can be obtained over an extended anatomic area and, thus, reveal the presence and the extent of presumed tissue injury.

Abstract

Denervation changes in muscle following damage to cranial and peripheral nerves can be observed on both CT and MR imaging studies. These findings are well described for cranial nerves (CN) V, X, XI, and XII. The CT findings of denervation atrophy due to CN VII dysfunction have been reported. We describe the MR imaging findings in two patients with perineural spread of tumor along CN VII. Both patients showed T2 prolongation and postcontrast enhancement in muscles of facial expression, suggestive of subacute denervation changes.

Abstract

Our objective was to determine the contribution of diffusion MR imaging to standard MR imaging in the neuroradiological evaluation of children less than 2 years of age. Echo-planar diffusion MR imaging was added to standard MR exams in 75 consecutive patients under the age of 2 years. Single-shot echo-planar spin-echo T2 weighted images (EPSE-T2) were acquired. Isotropic diffusion-weighted images (DWI), attenuation coefficient maps (ACM), and apparent diffusion co-efficient (ADC) maps were calculated offline from images obtained with diffusion gradients (b = 1000 s/mm2) in three orthogonal directions. Two neuroradiologists determined if EPSE-T2, DWI, or ACM contributed new information to spin-echo proton density (SE PD) and T2 studies. In 15 of 18 abnormalities detected in 8 patients with symptoms less than 1 week in duration, DWI and/or ACM added information to SE PD and T2. Diffusion sequences detected five new lesions, showed six lesions with greater conspicuity, and identified four lesions with different diffusion character. In patients with symptoms of more than 7 days duration, diffusion studies added no information. Isotropic diffusion MR contributed to lesion detection and characterization in infants when symptoms were less than 1 week in duration. Diffusion MR is useful in patients with leukodystrophies, metabolic disorders, and patients with acute ischemic lesions.

Abstract

Rabies encephalitis is a feared, virtually uniformly fatal form of central nervous system infection. The incidence of rabies encephalitis in the United States is almost certainly underestimated because of the predominance of bat-borne rabies, which can be spread without traumatic exposure. Because of its rarity in developed countries, rabies encephalitis has been seldom studied with modern imaging techniques.University-based teaching hospital.A case of pathologically confirmed rabies encephalitis is presented. Diagnosis of rabies was made by seroconversion testing while the patient was alive and was confirmed postmortem by the presence of rabies antigens and Negri bodies in the brain. The patient had 2 magnetic resonance studies done that showed dramatic abnormalities in the medulla and pons that correlated with features of the neurologic examination and hypothalamic-pituitary abnormalities.The patient had a fulminant encephalitic course that ended in death.Rabies is an uncommon cause of fatal encephalitis. Anatomic imaging studies such as computed tomographic and magnetic resonance scans have generally been negative in confirmed cases of rabies. We report a case of confirmed rabies with extensive brainstem and hypothalamic-pituitary abnormalities on magnetic resonance imaging. Although these findings are nonspecific, they should raise the clinical suspicion of rabies in the setting of aggressive encephalitis of unclear cause, and appropriate diagnostic tests should be performed.

Abstract

The authors describe two patients with clinical manifestations of the osmotic demyelination syndrome (ODS) and unusual MRI findings of gadolinium-enhancing peripheral cortical abnormalities. They propose that these represent extrapontine manifestations of ODS because neither patient had a notable hypoxic-ischemic insult. Recognizing this imaging appearance is important because prognosis in ODS may be less uniformly grim than for hypoxia-ischemia.

Abstract

To assess the safety, tolerability, and biologic and clinical activity of a solubilized complex comprised of human leukocyte antigen-DR2 with myelin basic protein84-102 (AG284)in patients with secondary progressive MS.Soluble species-specific major histocompatibility complex myelin basic protein91-103 complexes ameliorate disease in a dose-dependent manner when administered to SJL/J mice with chronic relapsing experimental allergic encephalomyelitis. Preincubation with AG284 reduces the proliferative response of a DR2-restricted, myelin basic protein84-102-reactive T cell clone, derived from a MS patient, to myelin basic protein84-102 in the presence of autologous antigen-presenting cells.Thirty-three patients with secondary progressive MS were randomly assigned to receive three alternate day IV doses of AG284 or placebo in a double-masked dose escalation study. The primary outcome was safety and tolerability. Secondary outcomes included a comparison of pre- and post-treatment gadolinium-enhanced brain MRI activity, Kurtzke Expanded Disability Status Scale, and Nine Hole Peg Test scores.The frequency of adverse events was similar in the AG284 and placebo recipients. No significant treatment effect was detected by Expanded Disability Status Scale, Nine Hole Peg Test, or number of new gadolinium-enhancing MRI lesions.AG284 as administered during this study was safe and well tolerated. Further studies are warranted to determine the biologic activity and clinical efficacy of this potential treatment for MS.

Abstract

Chordomas are locally aggressive malignant tumors of notochordal origin whose metastatic potential is increasingly recognized. Surgical pathway recurrence has been noted only rarely in the literature. We present three patients with clival chordomas whose sole or initial recurrence was along the pathway of prior surgical access. A characteristic mass found along the pathway of prior surgical access for resection of a chordoma should suggest recurrent chordoma.

Abstract

Elevated relative regional cerebral blood volume (rCBV) reflects the increased microvascularity that is associated with brain tumors. The purpose of this study was to investigate the potential role of rCBV in the determination of recurrent/residual disease in patients with treated gliomas.Thirty-one rCBV studies were performed in 19 patients with treated gliomas. All patients also had proton MR spectroscopy and conventional MR imaging. Regions of abnormality were identified on conventional MR images by two neuroradiologists and compared with rCBV and MR spectroscopic data. Metabolites and rCBV were quantified and compared in abnormal regions.In high-grade tumors, rCBV values were proportional to choline in regions of tumor and nonviable tissue. Although the presence of residual/recurrent disease was often ambiguous on conventional MR images, the rCBV maps indicated regions of elevated vascularity in all low-grade tumors and in 12 of 17 grade IV lesions. Regions of elevated and low rCBV corresponded well with spectra, indicating tumor and nonviable tissue, respectively.This study suggests that rCBV maps and MR spectroscopy are complementary techniques that may improve the detection of residual/recurrent tumor in patients with treated gliomas. Compared with the spectra, the rCBV maps may better reflect the heterogeneity of the tumor regions because of their higher resolution. The multiple markers of MR spectroscopy enable better discrimination between normal and abnormal tissue than do the rCBV maps.

Abstract

Alteration of cerebrospinal fluid (CSF) flow has been proposed as an important mechanism leading to the development of syringomyelia. We hypothesize that a "presyrinx" condition due to potentially reversible alteration in normal CSF flow exists and that its appearance may be due to variations in the competence of the central canal of the spinal cord.Five patients with clinical evidence of myelopathy, no history of spinal cord trauma, enlargement of the cervical spinal cord with T1 and T2 prolongation but no cavitation, evidence for altered or obstructed CSF flow, and no evidence of intramedullary tumor or a spinal vascular event underwent MR imaging before and after intervention that alleviated obstruction to CSF flow.Preoperatively, all patients demonstrated enlarged spinal cords and parenchymal T1 and T2 prolongation without cavitation. Results of magnetic resonance (MR) imaging examinations following intervention in all patients showed resolution of cord enlargement and normalization or improvement of cord signal abnormalities. In one patient with severe arachnoid adhesions who initially improved following decompression, late evolution into syringomyelia occurred in association with continued CSF obstruction.Nontraumatic obstruction of the CSF pathways in the spine may result in spinal cord parenchymal T2 prolongation that is reversible following restoration of patency of CSF pathways. We refer to this MR appearance as the "presyrinx" state and stress the importance of timely intervention to limit progression to syringomyelia.

Abstract

The central skull base is an anatomically complex region whose foundation is the sphenoid bone. It includes the sphenoid sinus, clivus, and sella turcica, as well as adjacent soft tissues such as the cavernous sinuses and nasopharynx. The central skull base may be affected by pathologies intrinsic to the sphenoid bone or by processes that arise in adjacent soft tissue and extend centrally to affect the central skull base. In general, this region is optimally imaged with magnetic resonance scanning, although in some cases computed tomography can provide complementary information. In this review, we will discuss a variety of pathologies that can affect the central skull base, such as neoplasms, infections, trauma, congenital malformations, and a variety of miscellaneous pathologies. We will discuss processes that can mimic neoplasia, such as aggressive polyposis and chronic inflammatory disease. For each pathology we will review clinical and imaging findings.

Application of new imaging techniques for the evaluation of squamous cell carcinoma of the head and neckSEMINARS IN ULTRASOUND CT AND MRIFischbein, N., Anzai, Y., Mukherji, S. K.1999; 20 (3): 187-212

Abstract

The past several years have seen dramatic changes in imaging of the head and neck. Technical improvements in CT and MRI coupled with their widespread availability have made cross-sectional imaging an important adjunct in evaluation of patients with disease of the extracranial head and neck. The most recent advances in head and neck imaging are from new metabolic and functional imaging techniques. The intent of this report is to provide an update on the potential role of positron emission tomography, new MRI agents, and magnetic resonance spectroscopy for evaluating squamous cell carcinoma of the extracranial head and neck.

Abstract

To document the late radiographic change following hyperfractionated craniospinal radiotherapy for primitive neuroectodermal tumor.We reviewed long-term MRI scans on 21 patients with standard risk and high risk primitive neuroectodermal tumor treated with hyperfractionated radiotherapy following surgical resection. High risk patients also received adjuvant chemotherapy. Long-term scans were defined as scan obtained at least 1 year from diagnosis. Clinical follow-up data was available on all patients.Twelve of 21 patients had MRI evidence of necrosis, telangiectasia, white matter changes, basal ganglia change, or cerebral atrophy consistent with radiation injury. No patient required treatment for the radiographic change.Slightly over half of the patients had evidence of long-term radiation effect following craniospinal axis radiotherapy. However, no patient had frank clinical symptoms related to the radiographic findings.

Abstract

To assess the usefulness of 2-[fluorine-18]fluoro-2-deoxy-D-glucose (FDG) positron emission tomography (PET) of the head and neck in locating occult primary lesions in patients with metastatic cervical adenopathy.Seventeen patients with metastatic cervical adenopathy of unknown primary origin were referred for FDG PET of the head and neck. All patients had undergone correlative anatomic imaging within 1 month of FDG PET. Surgical, clinical, and histopathologic findings were used to assess the performance of FDG PET.Increased apical lung uptake at FDG PET led to a biopsy-proved diagnosis of primary lung cancer in two patients. Of the remaining 15 patients, 10 had a focus of increased activity; directed biopsy of these sites led to confirmation of a primary carcinoma in seven patients. Correlative anatomic imaging failed to demonstrate the primary sites of disease in two of these seven patients. None of the five patients with negative FDG PET studies have manifested evidence of a primary site of disease during follow-up of 8-42 months (mean, 29 months).FDG PET allows effective localization of the unknown primary site of origin in metastatic head and neck cancer and can contribute substantially to patient care.

Abstract

Alteration of CSF flow has been proposed to be an important mechanism leading to the development of syringomyelia. We hypothesize that a "presyrinx" condition attributable to a potentially reversible alteration in normal CSF flow exists and that its appearance may be caused by variations in the competence of the central canal of the spinal cord.Five patients with clinical evidence of myelopathy, no history of spinal cord trauma, enlargement of the cervical spinal cord with T1 and T2 prolongation but no cavitation, evidence of altered or obstructed CSF flow, and no evidence of intramedullary tumor or a spinal vascular event underwent MR imaging before and after intervention that alleviated obstruction to CSF flow.Preoperatively, all patients had enlarged spinal cords and parenchymal T1 and T2 prolongation without cavitation. Results of MR examinations after intervention showed resolution of cord enlargement and normalization or improvement of cord signal abnormalities. In one patient with severe arachnoid adhesions who initially improved after decompression, late evolution into syringomyelia occurred in association with continued CSF obstruction.Nontraumatic obstruction of the CSF pathways in the spine may result in spinal cord parenchymal T2 prolongation that is reversible after restoration of patency of CSF pathways. We refer to this MR appearance as the "presyrinx" state and stress the importance of timely intervention to limit progression to syringomyelia.

Abstract

The use of positron emission tomography with 18F-fluorodeoxyglucose (FDG-PET) to detect residual/recurrent squamous cell carcinoma of the head and neck has been tested only in small groups of patients. Our purpose, therefore, was to evaluate the ability of this technique to detect the presence of tumor at both primary and nodal sites in a large cohort of patients.All patients referred for PET scanning over a 2.5-year period with a question of residual or recurrent squamous cell carcinoma of the head and neck were identified. Thirty-five of 44 patients had sufficient follow-up to be meaningful to our analysis (range, 6-33 months). PET scans were interpreted visually with knowledge of the clinical history and correlative anatomic imaging findings. Detection of disease involving primary and nodal sites was assessed independently. Additionally, because each patient had been referred in an attempt to resolve a specific clinical problem, the usefulness of PET in accurately addressing these questions was assessed.At the primary site, sensitivity and specificity for residual/recurrent disease were 100% and 64%, respectively; for nodal disease, sensitivity and specificity were 93% and 77%, respectively. In helping to resolve the clinical question being asked, the positive predictive value of the test result was 65% and the negative predictive value was 91%.The high sensitivity and negative predictive value of PET scanning in our cohort of patients suggest an important role for this technique in the care of patients with suspected residual/recurrent head and neck carcinoma. The lower figures obtained for specificity and positive predictive value reflect the fact that increased FDG uptake may be due to either tumor or inflammation.

Abstract

Sturge-Weber syndrome (SWS) is a neurocutaneous syndrome characterized by a facial nevus flammeus associated with seizures, developmental delay, and, often, with hemiparesis and hemianopia. On MRI, the most characteristic finding has been reported to be leptomeningeal enhancement, believed to represent leakage of contrast medium through the anomalous pial vessels that characterize the disease. We present a case of SWS with no evidence of leptomeningeal enhancement. This case illustrates that leptomeningeal enhancement need not be present in SWS, and the absence of this characteristic finding does not preclude the diagnosis.

Abstract

To determine if fast spin-echo T2 (FSE) is of equal value to flow-sensitive 2D cine phase-contrast (CPC) to assess patency of endoscopic third ventriculocisternostomies (VC).We reviewed clinical charts and MR scans of 27 patients who underwent third VC for treatment of obstructive hydrocephalus. Thirty-nine postoperative scans included both sequences and were assessed for the presence or absence of flow-related signal changes.In 28 cases, FSE, CPC, and clinical findings suggested patency. In 1 case, CPC and FSE suggested occlusion, which was confirmed clinically and operatively. In the remaining cases, FSE showed better clinical correlation than did CPC.The assessment of third VC patency with FSE, a sequence available on most clinical scanners without a requirement for special hardware and software, is at least as sensitive in the qualitative assessment of VC function as CPC.

Abstract

Patients infected with HIV have severely depressed immune function and are therefore vulnerable to many infectious and neoplastic processes. Head and neck manifestations initially were reported in approximately 40% of patients with AIDS, but in the course of HIV infection and progression to full-blown AIDS, it is now recognized that most patients have abnormalities on head and neck examination at some point in their disease. These manifestations range from relatively benign lymphoid hypertrophy or candidal mucositis to life-threatening fungal infections and high-grade lymphomas. This article reviews the spectrum of imaging findings associated with otolaryngologic diseases in this patient population.

Abstract

Although tumors of the brain stem have traditionally been classified as a single entity, these tumors are increasingly being recognized as a heterogeneous group, with some subgroups having better prognoses for long-term survival. Although several systems for classification of brain stem tumors have been proposed, none have been based on data derived from contrast-enhanced magnetic resonance (MR) imaging. In this review, we present a classification scheme based on our review of the literature and of the MR scans of 64 patients with brain stem tumors. In addition, we assess the contribution of gadolinium to the classification of brain stem tumors and correlate the various tumor subtypes, based on MR appearance, with prognosis. Our results suggest that the most important factor in determining prognosis based on MR characteristics is whether the tumor is diffuse or focal. Focal tumors have an excellent prognosis regardless of the site of tumor origin. Diffuse tumors of the mesencephalon and pons have a significantly poorer prognosis than focal tumors (p = 0.0013), with diffuse pontine tumors having the worst prognosis. Differentiation of diffuse and focal medullary tumors was difficult, possibly explaining the lack of significant difference in the survival of patients with diffuse versus focal medullary tumors. The presence or absence of enhancement after the administration of paramagnetic contrast has no significant relation with outcome, overall or within specific tumor subgroups.